How do you solve x-2y equals 5 and x equals y plus 2 with method of substitution?

Answer 1

OK, one way to solve systems of linear equations is using substitution. You have:

x-2y=5 and x=y+2

The first step is to solve for one of the variables (x or y) on the easiest-to-solve equation. However, they have already solved for x in the second equation:

x=y+2

Now substitute y+2 into every x on the other equation:

x-2y=5

(y+2)-2y=5 ;Plug in y+2 into all the x's

y+2-2y=5 ;Distribute the "understood" 1

2-y=5 ;Combine the y's

-y=3 ;Subtract 2 to both sides

y=(-3) ;Divide both sides by -1

Now that you have what y is equal to, plug that back into x=y+2:

x=(-3)+2 ;Plug in -3 for y

x=-1

Your solution for both equations is (-1,-3).