Question

How do you factor `7a^2-ab+28a-4b`?

Answer 1

There are 4 terms, so use the grouping method to create common factors.

Explanation:

`(7a^2 - ab) + (28a - 4b)` Each bracket has a common factor.
= `a(7a-b) + 4(7a - b)` This creates a common bracket.
= `(7a-b)(a+4)`