4x+y=16 multiply both sides by -3 and will get
2x+3y=-2
-12x -3y = -48
2x +3y = -2
--------------------------
-10x 0 = -50
-10x = -50
x = -50/(-10) = 5
x = 5
4x+y=16
4*5+y=16
20+y=16
y = 16-20
y = -4
x = 5
y = - 4
hope helped
F(x) = 4x - 9
let f(x) = y, this implies that x = f⁻¹(y)
y = 4x - 9 Let us solve for x.
4x - 9 = y
4x = y + 9
x = (y + 9)/4
Recall that x = f⁻¹(y),
x = (y + 9)/4
f⁻¹(y) = (y + 9)/4
That means that for f⁻¹(x)
f⁻¹(x) = (x + 9)/4
Hope this explains it.