Question

Which statement correctly explains how Dana can solve the following system of linear equations for x using the elimination method?
4x+8y=20
-4x+2y= -30
Add the two equations, solve for y, and then substitute –1 for y to find x.
Multiply the bottom equation by –4, solve for y, and then substitute –1 for y to find x.
Multiply the bottom equation by –1, combine the two equations, solve for y, and then substitute 1 for y to find x.
Multiply the two equations, solve for y, and then substitute 1 for y to find x.

Answer 1

1. The correct statement is the first one, which is: Add the two equations, solve for y, and then substitute –1 for y to find x.

 2. Therefore, you have the following system of equations:

 4x+8y=20
 -4x+2y= -30

 3. When you add the two equations, and clear the variable "y", you obtain:

 10y=-10
 y=-1

 4. Now, you must substitute -1 for y (y=-1) to find x, as below:

 4x+8y=20
 4x+8(-1)=20
 4x-8=20
 4x=20+8
 4x=28
 x=28/4
 x=7

Answer 2

Answer:

A

Step-by-step explanation:

3dg 2020 answer