To find the intersection, you need to substitute the y-value from the second equation into the first equation. Rearrange the second equation so that it is equal to y.
-y = 5x + 1
-1(-y) = -1(5x + 1)
y = -5x - 1
Substitute this equation into the y-value of the first equation.
2y = -x + 3
2(-5x - 1) = -x + 3
-10x - 2 = -x + 3
(-10x - 2) + 2 = (-x + 3) + 2
-10x = -x + 5
(-10x) + x = (-x + 5) + x
-9x = 5
(-9x)/(-9) = (5)/(-9)
x = -5/9
Plug this x value into one of the equations and solve for y.