Nine more than a number is equal to three less than the square of the same number. Find the number.

Answer 1

x = the number

x+9 = nine more than the number

x^2 - 3 = three less than the square of the number

those two expressions are equal, so equate and solve for x:

x + 9 = x^2 - 3

x^2 - x - 12 = 0

factor

(x-4)(x+3) = 0

x = 4 or -3