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| 07 Oct 2016 05:16 PM |
>What if the smaller number is negative?? -4 x 5 = 20 or -20?
doesn't matter which number is smaller, negative times a positive always equals a negative
negative times a negative always = positive and so does positive x positive
Iᴛ ᴀɪɴᴛ ᴇᴀsʏ, ʙᴇɪɴɢ Cʜᴇᴇsᴇʏ. |
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| 07 Oct 2016 05:17 PM |
I think this dude's problem lies right here...
"POSITIVE 4 plus NEGATIVE 2" Should be POSITIVE 4 *minus* NEGATIVE 2" which, as everyone else has already said, is flipped to make it positive 4 plus positive 2. 6. |
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| 07 Oct 2016 05:17 PM |
DUDE I'm joking I'm Asian as can be
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| 07 Oct 2016 05:17 PM |
we did learn something similar to keep-change-change, and thats how i get my answer, i just dont see why though bc usually when u see 4-2 you wanna put 2, but i forgot its negative and if u do 4+(-2) then it'd be 2
but ya we learned KFC, Keep-Flip-Change |
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| 07 Oct 2016 05:18 PM |
OMFG SHUT UP ITS NOT THAT HARD YOU #######################ING SLOW
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| 07 Oct 2016 05:18 PM |
i have no problem with the dividing and multiplying thats easy, i already know
positive and positive = positive negative x positive = ALWAYS NEGATIVE negative x negative = ALWAYS POSITIVE |
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| 07 Oct 2016 05:20 PM |
I NEVER SAID IT WAS HARD I JUST SAID I DONT UNDERSTAND WHY THO 4- -2 IT LOOKS LIKE 4-2 SO IT SHOULD BE 2, IK HOW TO GET THE ANSWER AND WHAT THE ANSWER IS I JUST SAID IT LOOKS LIKE 4-2 SO I WAS THINKING IT SHOULD BE 2 |
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| 07 Oct 2016 05:22 PM |
People make that mistake often in math. You can't just "get rid" of signs and things. It's like the law of conservation of math I guess. |
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| 07 Oct 2016 05:30 PM |
Fam hold this ▉ ▉ ▉ ▉ ▉▉▉▉ real quick for me
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| 07 Oct 2016 05:32 PM |
| sure, i'lll hold the L for u, but i'lll give it back, so why hand me it if im just gonna give it back? what kinda bulll sense that make? |
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| 07 Oct 2016 05:50 PM |
"bull sense" Hold this ▉ ▉ ▉ ▉ ▉▉▉▉
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| 07 Oct 2016 05:51 PM |
| why do u try to fit in with all these youtube comment section memes and try to stay hip or trendy, its not cool tryna be someone u aint just be urself bro |
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| 07 Oct 2016 05:53 PM |
With a post like that, no wonder you dont get integers.
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| 07 Oct 2016 05:55 PM |
| ik how to get the answer i just look at it a different way, unlike yo following #### i bet u look at it the same way as 96% of other people do, idk if thats a good thing or not but i'd like to be unique and be myself so i stand out instead of looking like a #### clone made in a #### factory |
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| 07 Oct 2016 06:04 PM |
■■■■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■ □□■□□□□■□□□■□□□□■□□□□■□□□□□□■□□□□□□■□□□□□□■□□□■□□■□□□□□□■□□□■ □□■□□□□■■■■■□□□□■□□□□■□□■■□□■□□■■□□■■■□□□□■■■■■□□■■■□□□□■□□□■ □□■□□□□■□■□□□□□□■□□□□■□□□■□□■□□□■□□■□□□□□□■□■□□□□■□□□□□□■□□□■ □□■□□□□■□□■■□□■■■■■□□■■■■■□□■■■■■□□■■■■■□□■□□■■□□■■■■■□□■■■■■
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padam11
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| Joined: 11 Feb 2013 |
| Total Posts: 15774 |
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| 07 Oct 2016 06:25 PM |
| mocking OP isn't actually helping the guy... and you learn this in 6th and ### ##### so i don't know why everyone is surprised and don't just expect a 13 year old to ### #### school math or something, people learn differently and in different speeds "Float like a butterfly, sting like a bee. His hands can't hit what his eyes can't see." -- Muhammad Ali | AC⚡DC |
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padam11
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| Joined: 11 Feb 2013 |
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| 07 Oct 2016 06:26 PM |
this filter
"Float like a butterfly, sting like a bee. His hands can't hit what his eyes can't see." -- Muhammad Ali | AC⚡DC |
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| 07 Oct 2016 07:31 PM |
Ignore the entitled people on this thread
Here's another way to think about it:
Think about a number line. When you do 4 - 2 (not 4 - (-2)), you count 4 places to the right until you reach 4, then the "- 2" tells you to move 2 places to the left, until you reach 2. 4 - 2 = 2.
What about negative numbers? When you do 4 - (-2), you count 4 places to the right, and then...what? Well, you're basically subtracting the opposite of 2. And if you're subtracting the opposite of 2, you're adding 2. The two negative symbols cancel out and become 4 + 2 = 6.
***RULE: If you are subtracting a negative, the two negative signs turn into one positive.*** You must memorize this.
5 - 4 = 1. 5 - (-4) = 9. Because 5 - (-4) turns into 5 + 4.
10 - 10 = 0. 10 - (-10) = 20.
10 + (-10) = 0. 10 - (-10) = 20.
***RULE: If you are multiplying a positive by a negative, your answer will be negative. If you are multiplying a negative by a negative, your answer will be positive.*** You must memorize this.
2 * 2 = 4. 2 * (-2) = -4. (-2) * (-2) = 4.
3 * 6 = 18. (-3) * 6 = -18. (-3) * (-6) = 18. |
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| 07 Oct 2016 07:32 PM |
If Da Signs Are THe Same, Its Positive!!!!! (UNLESS ITS AN ODD NUMBER OF NEGATIVES LOL ))))))
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eelee345
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| 07 Oct 2016 08:06 PM |
If you ever want to go into a career in math, you have to know your negatives. Period.
For example, here is a basic type 2 projectile motion question. I'll show you how key the negatives are to the right answer.
A cricket ball is hit upwards at 20 m/s at an angle of 30°. How far away did it hit the ground? What was the maximum height achieved by the ball? How long was it until the ball hit the ground?
I can calculate all three of those, but if I don't do my negatives right, I will get the wrong answer.
Here's what I have to do. I know that the angle is 30°, and I know the hypotenuse. So, to find the y velocity vector, it should be simple.
sinθ = opp/hyp hyp*sin30° = opp 20 m/s*sin30° = opp sin30° = 0.5 20 m/s*0.5 = 10 m/s
The y velocity vector is 10 m/s. Since the shape of type 2 projectile motion is parabolic, I automatically know that if the y velocity vector at the start of the flight is 10 m/s, it must be -10 m/s at the end of the flight. This is where the negatives come into play- if I pu# ###m/s, that is WRONG, and I ge# the wrong answer.
Now, I just need to calculate the x velocity vector and the time and I will have my part a) answer.
cosθ = adj/hyp hyp*cos30° = adj 20 m/s*cos30° = adj cos30° = 0.866 20 m/s*0.866 = 17.32 m/s
Right, x velocity vector done. Pretty simple. Now, here's when things begin getting a tad more difficult- getting your negatives right.
I am dealing with the y vector- the only thing constant across the vectors is time. So, I can calculate the time in both vectors. WATCH HOW I PLACE MY NEGATIVES. The final velocity is -10 m/s, and the initial 10 m/s, and acceleration due to gravity is NEGATIVE 9.81 m/s² (-9.81 m/s².) This is the Y VECTOR.
a = vf-vi/t (some basic algebra later...) vf-vi/a = t (-10 m/s) - 10 m/s / (-9.81 m/s²) = t 2.038735984 s = t
How long was it until the ball hit the ground? -- 2.04 s
If I had even misplaced ONE NEGATIVE, I would've got the wrong answer. But this question isn't even close to being done. I haven't solved anything IMPORTANT yet. Now, I have the x velocity vector and I have the time. So I can calculate the x distance, or the distance away from the hitting point.
v = d/t (basic algebra...) tv = d (###############17.32 m/s) = d 35.27 m = d 35 m = d
How far away did it hit the ground? -- 35 m.
What was the maximum height achieved by the ball?
Since I've already found the velocity vectors, and the time. This is quite simple. At the height of a parabolic trajectory, the velocity is always 0 m/s. Therefore, I can find the highest point by this simple equation. Just to make it easier for myself, I'll consider the initial velocity to be 0 m/s- BUT I'LL HAVE TO HALVE THE TIME, THEN. Once again, WATCH THE NEGATIVES.
d = vit + 1/2at² d = 1/2at² (vi is negative and thus that portion of the equation is cancelled out) d = 1/2at² d = 1/2(-9.81 m/s²)(2.04 s/2)² d = -5.103162 m
Since it's going downwards, the negative is simply a VECTOR here.
d = 5.103162 m d = 5.10 m
What was the maximum height achieved by the ball? -- 5.1 m.
Job done. Simply put, if you don't learn how to use your negatives, you will not be able to cope with basic physics, basically cutting off an entire sector of your life. |
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