When 10b =5 (√c+2) is solved for c one equation is c= (2b-2) ^2 which of the following is an equivalent to find c

I will show all the steps to lead to the solution.

1) 10b = 5 (√c + 2)  < starting equation

2) divide by 5 => 2 b = √c + 2

3) subtract 2 => 2b - 2 = √c

4) raise to the power 2 => (2b - 2)^2 = c, which is the expression given.

Now these are two equivalent forms:

1) extract 2 from the parentheses: c = 4 (b -1)^2

2) expand the parentheses: c = 4b^2 - 8b + 4)