Question

solve system of equation
y=5x-2
y=2x+10
AND
x=-2y-1
2x+y=-20

Answer 1

system 1: equate the y's, but write in terms of x:

5x-2=2x+10
3x=12
x=4
back sub for y
y=5(4)-2=18

Answer 2

make the first 2 equations equal to one another and solve for x, then for the last 2 equations isolate y for each side and do the same as before

Answer 3

system 2: sub x from equation 1 into eqn 2, but write in terms of y

2(-2y-1)+y=-20
-4y-2+y=-20
-3y=-18
y=6
back sub into the first eqn to get x
x=-2(6)-1=-12-1=-13