Answer:
a) ab(5a + 15b - 2ab)
b) (5a + 9b)(5a - b)
Explanation:
When you are factoring, you will factor out "common factors", which are numbers/variables that are shared by all terms within the given expression.
A "term" is a standalone group of either number, variable, exponents, or a mix of them.
a) 5a²b + 15ab² - 2a²b²
For question a, note that they all have the variables a & b, but that they do not all share the same factors.
Factors of:
5: 1 , 5
15: 1 , 3 , 5 , 15
2: 1 , 2
In this case, factor out one a and one b:
ab(5a + 15b - 2ab) is your answer.
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b) 25a² - 81b²
You can find perfect squares. Note that it is a² - b², which means that it will factor as such:
(a² - b²) = (a + b)(a - b)
(25a² - 81b²) = (5a + 9b)(5a - b)
(5a + 9b)(5a - b) is your answer.
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