Question

5x² – 22x – 15 = 0

Answer 1

Given: 5x² – 22x – 15 = 0

On splitting the middle term –22x as – 25x + 3x, we get:

5x² – 25x + 3x – 15 = 0

$\Rightarrow$5x(x – 5) + 3(x – 5) = 0

$\Rightarrow$(x – 5) (5x + 3) = 0

We know that if the product of two numbers is zero, then at least one of them must be zero.

Thus,

x – 5 = 0 or 5x + 3 = 0
$\Rightarrow$x = 5 or x = –$\frac{3}{5}$
Therefore, the solution of the given equation is x = 5, – $\frac{3}{5}$.