take 1/2 of the coefficient of the middle term, then square it
i.e.
1/2(15) = 15/2
now we square this: (15/2)^2 = 225/4 or 56.25 in decimals
c = 225/4
what is the value of c to make this expression a perfect square trinomial?
x^2-15x+c
1 answer