Question

Solve the following quadratic equation by

factorisation.

5m² = 22m + 15

Answer 1

5m² = 22m + 15  

\[\Rightarrow 5 m^2 - 22m - 15 = 0\]
\[ \Rightarrow 5 m^2 - 25m + 3m - 15 = 0\]
\[ \Rightarrow 5m\left( m - 5 \right) + 3\left( m - 5 \right) = 0\]
\[ \Rightarrow \left( 5m + 3 \right)\left( m - 5 \right) = 0\]
\[ \Rightarrow \left( 5m + 3 \right) = 0 or \left( m - 5 \right) = 0\]
\[ \Rightarrow m = \frac{- 3}{5} \text{ or } m = 5\] 

So,  \[\frac{- 3}{5} \text{ and } 5\] are the roots of the given quadratic equation.