finding restrictions: 4a^2-b^2-2a+b / (2a+b)^2-1

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.
foood
Posts: 8
Joined: Sat Oct 29, 2011 7:42 pm
Contact:

finding restrictions: 4a^2-b^2-2a+b / (2a+b)^2-1

ok i understand how to solve the problem, but i dont get how to get the restrictions.

i have to solve this problem and then put restrictions on it
4a^2-b^2-2a+b / (2a+b)^2-1

the answer is 2a+b / 2a+b+1
but on my answer sheet the restrictions also says b is not equal to 1-2a and -(2a+1)
my teacher also said it is 2a+b not equal to -1

i dont know how to find restrictions -____-

stapel_eliz
Posts: 1628
Joined: Mon Dec 08, 2008 4:22 pm
Contact:
ok i understand how to solve the problem, but i dont get how to get the restrictions.
Assuming "solve" means "simplify", the restrictions come from the factors you cancelled off. They had zeroes which would have caused division by zero. When you cancelled them off, you changed the domain.

Put those restrictions (that is, the values that would originally have caused division by zero) back in to make the simplified form match the original form.