Express x2+4x-7 in the form (x + a) 2-b where a and b are integers.

(x+2) ^2-11

Step-by-step explanation:

(x+a) ^2-b=x2+2ax+a2-b

Comparing the co-efficients of the above with x2+4x-7 we get,

2a=4, a=2

a2-b=-7

Solving for b given a, b=11

Substituting value of a and b we get,

(x+2) 2-11