"How many" all day

Use AM-GM for the second equation $7= 5.\frac{3}{5}x+3.\frac{2}{3}y\geq 8\sqrt[8]{\frac{3^2.2^3}{5^5}x^5y^3}=8$ As can be seen, the inequality above is wrong so $None$ is the correct answer

*For anyone that questioned: " $x,y$ aren't positive so we can't use AM-GM". In the first equation, notice that $x,y$ have odd power, and $RHS>0$ , so $x,y$ must be both positive or both negative. If they're negatives, then the second equation'll be incorrect since $LHS<0$ and $RHS>0$ . Therefore they must be positive