Question

Solve the system of equations:

3x + 8y = 72
-5x - 2y = -52

Answer 1

multiply 2nd equation with 4 and add them

Answer 2

4? How do you even get 4?

Answer 3

if you do you it...y would be eliminated

Answer 4

That doesn't answer my question.. Where do you even get a 4 out of this equation?

Answer 5

Ho did you figure t that you need to multiply it by 4?

Answer 6

The elimination method works by eliminating the y's or the x's. To do this, sometimes you have to multiply one or sometimes both of the equations by a number for this to occur.
souvik is right in telling you to multiply the 2nd equation by 4 because if you do that, you will find that the y's will cancel each other out. Try it. What do you get when you multiply the 2nd equation by 4 ?

Answer 7

-20x-8y=-208

Answer 8

Let me explain more....if you multiply the 2nd equation by 4 you will get -20x - 8y = - 208. Now, when you add the equations, you will see that the 1st equation has a 8y and the 2nd equation has a -8y, and they cancel out. Do you understand ?

Answer 9

Yes

Answer 10

3x + 8y = 72
-5x - 2y = -52 -->(4)-5x - 2y = -52
--------------
3x + 8y = 72
-20x -8y = - 208
---------------add
-17x = - 136
x = 8
now sub 8 in for x in either of the original equations to get y.
Does this make sense to you ?

Answer 11

This is the easiest way, however, you could have multiplied the 1st equation by 5 and the 2nd equation by 3, and that would make the x's cancel out. Either way, you should come up with the same answer.

Answer 12

Yes, I get it now..

Answer 13

good to hear :)

Answer 14

(8, 6) ?

Answer 15

Let me check...hold on

Answer 16

x=8 and y=6 using the elimination method as they are describing.

Answer 17

right...!

Answer 18

x = 8
now sub 8 in for x
3x + 8y = 72
3(8) + 8y = 72
24 + 8y = 72
8y = 72 - 24
8y = 48
y = 6
you can check your answers by subbing in your info in either of the original equations...
-5x - 2y = -52
-5(8) -2(6) = -52
-40 - 12 = - 52
-52 = -52 (correct)
If they come out even, then it is correct, if not, then a mistake was made or their is no solution.
Yes....answer is (8,6)

Answer 19

Yay, thank you.! c:

Answer 20

anytime :)

Answer 21

Yay math!