What is the value of x?
We have that
(x + 1) ( x + 1 + 14) x ( x + 21) simplify
(x + 1) ( x + 15) = x^2 + 21x
x^2 + 16x + 15 = x^2 + 21x subtract x^2 from both sides
16x + 15 = 21x
15 + 16x - 21x = 0
15 - 5x = 0
15 = 5x
x = 3 you are correct !!!