Answer:
B.
Step-by-step explanation:
[tex]x^{2} -y^{2}[/tex] = (x + y)(x - y)
So, if x + y = 7/10, and x - y = 5/14, [tex]x^{2} -y^{2}[/tex] = (7/10) * (5/14) = 35/140 = 1/4.
(1/2)^2 = 1/4
So, (B) (1/2)^2 is your answer!
Hope this helps!
