George starts with a number. He takes away 7, then squares it, adds 6, subtracts 13, multiplies it by 4 and subtracts 1.

He ends up with 7.

What was George's original number?

10 or 4.

Step-by-step explanation:

[ (x - 7) ^2 + 6 - 13 ] * 4 - 1 = 7

(x^2 - 14x + 49 - 7) * 4 - 1 = 7

4x^2 - 56x + 196 - 28 - 1 - 7 = 0

4x^2 - 56x + 160 = 0

4 (x^2 - 14x + 40) = 0

(x - 10) (x - 4) = 0

x = 10, 4