Question

A variable needs to be eliminated to solve the system of questions. Choose the correct first step: -x+2y=-158x-2y=-20A. Add to eliminate x BSubtract to eliminate yC Add to eliminate y D Subtract to eliminate y

Answer 1

The given equations are

`-x+2y=15`
`8x-2y=20`

Adding both equations

`(-x+2y)+(8x-2y)=15+20`

`7x=35`
`x=5`

Hence we get the value of x by adding the equations.

The coefficients of y of the equations are 2 and -2 respectively. so if we add both equations the y term will vanish.

The answer is

Add to eliminate y.