Question

How do you factor `a²+4b-ab-4a`?

Answer 1

`=(a-4)(a-b)`

Explanation:

We'll solve this by factoring by grouping:
`a^2+4b-ab-4a=a^2-ab-4a+4b`
`=a(a-b)-4(a-b)`
`=(a-4)(a-b)`