Question

Factorize :
a^2 +2a - 840=0​

Answer 1

$a {}^{2} + 2a - 840 \\ = a {}^{2} + 30a - 28a - 840 \\ = a(a + 30) - 28(a + 30) \\ = (a + 30)(a - 28)$

Answer 2

Answer:

read it according to steps given above.... try to understand, it's quiet simple...

Step-by-step explanation:

it can explained in two simple steps:1~~by simplifying 2a into 30a-28a which is equal to 2a.

2~~then factorise it in the regular middle term factorising method.