How do I solve this?(7x+5y)^2
Nothing to solve, since you don't have an equation.
If you want to expand your expression, then
(7x + 5y)^2
= (7x+5y)(7x+5y)
= 49x^2 + 70xy + 25y^2
If you want to expand your expression, then
(7x + 5y)^2
= (7x+5y)(7x+5y)
= 49x^2 + 70xy + 25y^2