Solve each of the following quadratic equations:
taking LCM
x2 + 4x - 5 = 7 cross multiplying
x2 + 4x - 12 = 0
Using the splitting middle term - the middle term of the general equation is divided in two such values that:
Product = a.c
For the given equation a = 1 b = 4 c = - 12
= 1. - 12 = - 12
And either of their sum or difference = b
= 4
Thus the two terms are 6 and - 2
Difference = 6 - 2 = 4
Product = 6. - 2 = - 12
x2 + 4x - 12 = 0
x2 + 6x - 2x - 12 = 0
x(x + 6) - 2(x + 6) = 0
(x + 6)(x - 2) = 0
(x + 6) = 0 or (x - 2) = 0
x = - 6 or x = 2
Hence the roots of equation are - 6 or 2.