What number goes in the question mark so that the quadratic is the square of a binomial? 9x^2 +6x+?
PLEASE ANSWER THANK YOU SO MUCH :)!
Let m be the mystery number.
9x2 + 6x + m = (3x)2 + 2(3x) + m
Now we can substitute a for 3x like this:
a2 + 2a + m
Now we don't have to worry about the coefficient of 9 on the first term....and so m is half the coefficient of the middle term squared.
m = ((1/2) * 2)^2 = 1^2 = 1
9x2 + 6x + 1 = (3x + 1)(3x + 1) = (3x + 1)2