5≤x≤9 it can also be reversed as 9≥x≥5 which is the same thing
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.
5x = 6x-7
subtract 6x from each side
-x=-7
x=7
42 degrees. Comment down if you need the explanation why
