3 years ago

A^2-b^2=21 a-b=3 what is the value of a+b

SAT

1 answer:

yaroslaw [1]3 years ago

7 0

The answer is 7.
(a + b)(a - b) = a ^ 2 - b ^ 2
So, (a + b)(a - b) is 21.
Since (a - b) is 3, divide 21 by 3 to get 7.

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