math problem

Test Preparation SAT Preparation
1

<p>i have a question on a math problem that is troubling me. the full problem can be found on page 705 of the bb second edition (problem 20), but this is the part that is troubling me: </p>

<p>prove that a(a + b) - (a+b) = 0 if a and b are both positive integers.</p>

<p>if anyone can prove this i would be grateful.</p>

<p>edit: my mistkae; this is no proof. it does not work for all positive integers. they want you to find a solutions. so i guess solve</p>

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<p>ok just in case anyone else is curious it is just simple factoring really. it totally slipped my mind: (a-1)(a+b)</p>

<p>so if a is 1, it is going to be 0 regardless of the value of 0.</p>

<p>this post isnt really necessary for me now…if somone wants, they are free to delete</p>