solve the system -x+y=2 and 4x-3y=-7

Question

-x+y=2 and 4x-3y=-7.

Answer 1

Elimination method

First equation -x+y = 2

Mulitiple to each side by 3.

-3x+3y = 6 ---> (1)

Second equation 4x-3y = -7 ---> (2)

To eliminate the y value add the equations (1)&(2).

-3x + 3y  = 6

4x - 3y  = -7

__________

x = -1

Substitute the x  value in (1).

-3 (-1 ) +3y = 6

3y = 6 - 3

3y = 3 ⇒  y =1

Solution x = -1 and y =1 .