Question

Four times the square of a positive number is eight times that number. Find the number.

Answer 1

2

Explanation:

Let x represent the number.

4x^2 = 8x . . . . . 4 times the square of a number is 8 times that number

4x^2 -8x = 0 . . . . subtract 8x

4x(x -2) = 0 . . . . . factor

x = 0 or x = 2 . . . . the product is zero when the factors are zero

The positive number is 2.