Question

Find the value(s) of k for which the expression is a perfect square trinomial.
49x^2-84x+k

Answer 1

Explanation:

step 1. the perfect square will look like this: (7x + a)(7x + a) = (7x + a)^2.

step 2. by performing FOIL you will get 49x^2 + 14xa + a^2.

step 3. 14a = 84. a = 6

step 4. a^2 = 36.

step 5. k = 36.