Question

1-a-72a^2 factorise
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Answer 1

Answer:

The answer is $(1-9a)(1+8a)$

Step-by-step explanation:

 $1-a-72a^2$

$=1-9a+8a-72a^2$, split the middle term

$=(1-9a)+(8a-72a^2)$, group the terms

$=(1-9a)+8a(1-9a)\\=(1-9a)(1+8a)$, take out the common factor