Question

x2+x-72=0 factorise
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Answer 1

Step-by-step explanation:

x2+x-72=0

x2+9x-8x-72=0

x(x+9)-8(x+9)=0

(x+9)(x-8) =0

x=8 or -9

Answer 2

$\sf \Large Solution!!$

We can just do middle term splitting to factorise this.

x²+x-72=0

x²+9x-8x-72=0

(x²+9x)(-8x-72)=0

x(x+9)-8(x+9)=0

(x-8)(x+9)=0

If we have to find the value of x, then

either x-8=0 => x=8

or x+9=0 => x=-9