Question

Factorise the expression: $x^2+5x-6$

• A. $(x+6)(x-1)$
• B. $(x+6)(x+1)$
• C. $(x+3)(x-2)$
• D. $(x+3)(x+2)$

Answer 1

The correct option is A $(x+6)(x-1)$

$x^2+5x-6=$

Given, the expression is $x^2+5x-6.$
Comparing the above expression with the identity
$x^2+(a+b)x+ab$
We note that,
$(a+b)=5$ and $ab=-6$
So,
$6+(-1)=5$ and $\left(6\right)(-1)=-6$
Hence,
$x^2+5x-6$
$=x^2+6x-x-6$
$=x(x+6)-1(x+6)$
$=(x+6)(x-1)$