To solve this equation, we first need to distribute the terms on the right side:

4 - 5x = 5x^2 - 40x - 10x + 40

Next, we combine like terms:

4 - 5x = 5x^2 - 50x + 40

Now, we move all terms to one side to set the equation to zero:

5x^2 - 45x - 36 = 0

Next, we can solve for x by factoring or using the quadratic formula.

Factoring, we get:

(5x + 4)(x - 9) = 0

Therefore, either 5x + 4 = 0 or x - 9 = 0

From this, we see that:

x = -4/5 or x = 9

So the solutions to the equation are x = -4/5 or x = 9.