What value of b makes the polynomial below a perfect square?
x2 + bx + 49
b =
a. 49
b. 9
c. 14
d. 25

Polynomials are perfect squares when the first term (term x2) and the third term (term 49) are both squares. In order to find the value of b, you must take the square root of the third term and multiply by the exponent in the first term. This means since the sqrt(49) is 7, and 7x2=14; then the correct answer is C. 14.

-- Remember this only works on perfect square polynomials.