Question

Use substitution to solve for y in the system of equations.

4x-2y=56

5x+y=28

A.Y=3
B.Y=-12
C.Y=-18
D.Y=12

Answer 1

@kaek98 Do you know substitution?

Answer 2

I don't know much of it. I know you replace y with a number

Answer 3

oh that's easy

Answer 4

put y =28-5x in first equation
solve for x
then find y

Answer 5

We 'll find x in terms of y from first equation, then substitute for x in the second.
I'll illustrate that

Answer 6

tell me the answer

Answer 7

after solving

Answer 8

\[4x-2y=56\]
Add 2y to both the sides
\[4x=56+2y\]
Divide both sides by 4
\[x=\frac{56+2y}{4}\]
Do you get this ? @kaek98

Answer 9

B.

Answer 10

@ash2326 It does somewhat.

Answer 11

Great now we have second equation
\[5x+y=28\]
Let's put the value of x found earlier
\[5\times \frac{(56+2y)}{4}+y=28\]
Multiply both sides by 4
\[4 \times (5\times \frac{(56+2y)}{4}+y)=4\times 28\]
\[5\times (56+2y)+4y=112\]
Can you try from here @kaek98

Answer 12

I have this one. When I put in -12 I came up with 112. But I can't get the first one

Answer 13

First one ?

Answer 14

4x-2y=56

Answer 15

We need to find y, you already found that y=-12
Now if you need to find x
\[4x-2y=56\]
put y=-12 here and solve for x

Answer 16

x= 8

Answer 17

yeah :) Good work :D

Answer 18

@ash2326 Do you think you could help me with another one?
I had someone helping me with it but they left

Answer 19

yeah, post that as a new question :)

Answer 20

Okay Thank you :)