How do you find the sum or difference of $(2a-4a^2+1)-(5a^2-2a-6)$ ?

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Answer 1 · 2016-12-18T13:31:36

$-9a^2 + 4a + 7$

First, expand the terms within parenthesis paying close attentions to the signs inside and out side the parenthesis:

$2a - 4a^2 + 1 - 5a^2 + 2a + 6$

Now, group like terms:

$- 4a^2 - 5a^2 + 2a + 2a + 1 + 6$

Next combine the like terms:

$(-4 - 5)a^2 + (2 + 2)a + 7$

$-9a^2 + 4a + 7$

How do you find the sum or difference of (2a-4a^2+1)-(5a^2-2a-6)(2a-4a^2+1)-(5a^2-2a-6)?