Question

Find the value of x, if a + 1 = 0 and x2 + ax – 6 = 0  

Answer 1

If a + 7 =0, then a = -7
and b + 10 =0, then b = − 10
Put these values of a and b in the given equation 

`12x^2 = (−7)x –(−10)`
⟹ `12x^2 + 7x – 10 = 0`
⟹ `12x^2 + 15x – 8x − 10 = 0`
⟹ `3x (4x + 5) – 2(4x + 5) = 0`
⟹ `(4x + 5) (3x – 2) = 0`
If `4x + 5 = 0  Or  3x – 2 =0

 Then X=`(-5)/4        or  x=2/3`