The equation shown below involves a perfect square trinomial. 4x2 + 20x + 25 = 7 Which of the following is a step in solving this equation? A. Take the square root of both sides B. Subtract 25 from both sides C. Square both sides D. Divide both sides by 4

4 x^2 + 20 x + 25 = 7

Divide both sides by 4:

x^2 + 5 x + 25/4 = 7/4

Write the left-hand side as a square:

(x + 5/2) ^2 = 7/4

Take the square root of both sides:

x + 5/2 = sqrt (7) / 2 or x + 5/2 = - sqrt (7) / 2

Subtract 5/2 from both sides:

x = sqrt (7) / 2 - 5/2 or x + 5/2 = - sqrt (7) / 2

Subtract 5/2 from both sides:

Answer: x = sqrt (7) / 2 - 5/2 or x = - 5/2 - sqrt (7) / 2