Question

Question 1(ii)
Find the roots of the following quadratic equations by factorisation:
(ii) $2x^2+x–6=0$

Answer 1

(ii)
$2x^2+x-6$
$=2x^2+4x-3x-6$
(Splitting the middle term x as 4x-3x because $4x\times -3x=-12x^2$)
$=2x(x+2)-3(x+2)=(x+2)(2x-3)$
Roots of this equation are the values for which $(x+2)(2x-3)=0$
$\therefore x+2=0or2x-3=0\Rightarrow x=-2orx=\frac{3}{2}$