Question

5m2 = 22m + 15 ( solve the following quadratic equation by factorisation)

Answer 1

5m^2-22m-15=0
5m^2-25m +3m-15=0
5m(m-5)+3(m-5)=0
(m-5)(5m+3)=0
m=5, m=-3/5

Answer 2

$5 {x}^{2} = 22x + 15 \\ 5 {x}^{2} - 22x - 15 = 0$
We need to split the coefficient of x in two numbers whose product is (-15)×(5)=-75 and whose sum is -22.
Upon thinking, we find that such numbers are -25 and 3.
$5 {x }^{2} - 25x + 3x - 15 = 0 \\ 5x(x - 5) + 3(x - 5) = 0 \\ (x - 5)(5x + 3) = 0$
Now for this product to be zero, either one or both of these have to be zero. Thus, we get
$x = 5$
or ( and )
$x = \frac{ - 5}{3}$