Question

Select all of the following that are quadratic equations. 7x2 + 14x = 0 x3 - 3x2 + 1 = 0 5x - 7 = 0 x2 + 3x -5 = 0 x - 5 = 9x + 7 x2 - x = 3x + 7

Answer 1

7x2 + 14x = 0

x2 + 3x -5 = 0

x2 - x = 3x + 7

Explanation:

A quadratic equation has the highest power of x to the second power. It must have x to the second power

7x2 + 14x = 0 quadratic

x3 - 3x2 + 1 = 0 not quadratic but cubic

5x - 7 = 0 not quadratic but linear

x2 + 3x -5 = 0 quadratic

x - 5 = 9x + 7 not quadratic but linear

x2 - x = 3x + 7 quadratic