Which statement justified the given ordered pair as a solution to the system of equations

(-1, -13), (y=3x-10), (y=-2x-15)

subbing x = -1 into the first equation gives you

3(-1) - 10 = -13, so it satisfies the first
subbing x = -1 into the 2nd equation gives you
-2(-1) - 15 = -13, so it satisfies the 2nd as well

(-1,-3) must be the intersection point, or the solution to
y=3x-10 and y=-2x-15