Given:
On multiplying both sides by x, we get:
x2 + 20 – 12x = 0
x2 – 12x + 20 = 0
On splitting the middle term –12x as –10x – 2x, we get:
x2 – 10x – 2x + 20 = 0
x(x – 10) – 2(x – 10) = 0
(x – 10) (x – 2) = 0
We know that if the product of two numbers is zero, then at least one of them must be zero.
Thus,
x – 10 = 0 or x – 2 = 0
x = 10 or x = 2
Therefore, the solution of the given equation is x = 10, 2.