Question

Expand the following using an identity:
1) (x - 5/8 y)^2
2) (1/3 m + n - 6)^2

Answer 1

1)(x-5/8y)^2
[(a-b)^2=a^2-2ab+b^2]
=x^2-2*x*5/8y+(5/8y)^2
=x^2-5x/4y+25/64y^2