we have
4x+5y=2 ------> equation A
x+2y=-1
isolate the variable x
x=-1-2y ------> equation B
substitute equation B in equation A
4(-1-2y)+5y=2
solve for y
-4-8y+5y=2
8y-5y=-4-2
3y=-6
y=-2
Find the value of x
x=-1-2y
x=-1-2(-2)
x=-1+4
x=3
answer is
solution is (3,-2)
