(0.456 * 0.456 – 0.228 * 0.228) / (0.456 + 0.228) = ________?

A. 0.228
B. 0.456
C. 0.684
D. 1.0

Explanation:

(0.456 * 0.456 – 0.228 * 0.228) / (0.456 + 0.228)

This is the form of 7x/60 = 7 = a – b = 0.466 – 0.228 = 0.228