Question

itle Solve the following quadritic equations by completing the square: i) x² + 12x+ = 15+ 1i) x² - 4x +36=0

Answer 1

SOLUTION:

1 ii) x² - 14x +36 = 0

Using the method of completing the square,

x² - 14x +36 = 0

x^2 - 14 x = 0 - 36

x^2 - 14 x = -36

coefficient of x = -14

Divide by 2 = - 7

Square = ( - 7 ) ^2 = 49

Add 49 on both sides, we have:

x^2 - 14 x + 49 = - 36 + 49

Factorizing the Left -Hand Side of the Equation, we have:

( x - 7 ) ^2 = 13

Square - root both sides, we have :

x - 7 = + 3 .6056 or - 3. 6056

x = 7 + 3. 6056 or 7 - 3. 6056

x = 10 . 6056 or 3.3944