Question

express x^2+4x-7 in the form (x-a)^2-b

Answer 1

Answer:

See the explanation

Step-by-step explanation:

Using the identity $a^2+b^2+2ab=(a+b)^2$

The expression $x^2+4x-7$

                         $=(x)^2+2(x)(2)-7$

                         $=[(x)^2+2(x)(2)+(2)^2]-7-(2)^2$, add and subtract $(2)^2$

                         $=(x+2)^2-7-4\\=(x+2)^2-11\\=(x-(-2))^2-11$, which is clearly in the required form