Question

Which are the solutions of x2 = –11x + 4?

Answer 1

x = 0.35 or x = -11.35

Explanation:

Points to remember

Solution of a quadratic equation ax² + bx + c = 0

x = [-b ± √(b² - 4ac)]/2a

It is given that, x² = –11x + 4

x² + 11x - 4 = 0

To find the solution

Here a = 1, b = 11 and c = -4

x = [-b ± √(b² - 4ac)]/2a

x = [-11 ± √(11² - 4 * 1 * (-4))]/2*1

= [-11 ± √(121 + 16)]2

= [-11 ± √137]/2

= [-11 ± 11.70]/2

x = -11 + 11.70 or x = -11 - 11.70

x = 0.35 or x = -11.35