Find the roots of 4x square + 4x - 15 = 0 by completing square method
Answers
Answered by
0
Answer:
x = 3/2 , -5/2
Note:
★ The possible values of the variable which satisfy the given equation are called its roots .
★ A quadratic equation can have atmost two roots .
Solution:
Here,
The given quadratic equation is ;
4x² + 4x - 15 = 0 .
We need to find the roots of the given quadratic equation by Complete squaring method .
Thus,
=> 4x² + 4x - 15 = 0
=> (2x)² + 2•2x•1 + 1² - 1² - 15 = 0
=> (2x² + 2•2x•1 + 1²) - 1 - 15 = 0
=> (2x + 1)² = 1 + 15
=> (2x + 1)² = 16
=> 2x + 1 = √16
=> 2x + 1 = ± 4
=> 2x = - 1 ± 4
=> x = (-1 ± 4)/2
=> x = (-1 + 4)/2 , (-1 - 4)/2
=> x = 3/2 , -5/2
Hence,
The required answer is ; x = 3/2 , -5/2
Similar questions