You have the following equations:
2. -2(-2x+4) = 16
3. -30 = 6(f-3)
In order to solve the previous equations you proceed as follow:
-2(-2x+4) = 16 apply distribution property
-2(-2x) -2(4) = 16
4x - 8 = 16 subtract 8 both sides
4x = 16 - 8
4x = 8 divide by 4 both sides
x = 8/4
x = 2
Hence the solution is x = 2
-30 = 6(f-3) apply distribution property
-30 = 6(f) - 6(3)
-30 = 6f - 18 sum 18 both sides
-30 + 18 = 6f
-12 = 6f divide by 6 both sides
(-12)/6 = f
-2 = f
Hence, the solution is f = -2