Question

What number should be added to the expression x2 + 4x to change it into a perfect square trinomial?

A:1
B:8
C:2
D:4

Answer 1

To make a perfect square trinomial you take the "b" and divide it by 2, square that value, and add it to the expression. This will make a perfect square trinomial.

b = 4 so.....
4/2 = 2
2^2 = 4
add 4 to the expression x^2 + 4x + 4 = (x + 2) ^2
LETTER D