<s>[INST] How to find Ratio And proportion If $\frac{4x+3y}{4x-3y}=\frac{7}{5}$.Find the Value of the $\frac{2x^2-11y^2}{2x^2+11y^2}$.
Okay I just want hint how to solve this problem.
 [/INST] Just notice that
$$\frac{4x+3y}{4x-3y}=\frac{7}{5}\qquad\implies\qquad 5(4x+3y)=7(4x-3y)\qquad\implies\qquad 36y=8x$$
So $y=\frac{2}{9}x$, then
$$\frac{2x^2-11y^2}{2x^2+11y^2}=\frac{2x^2-\frac{44}{81}x^2}{2x^2+\frac{44}{81}x^2}=\frac{2\cdot 81-44}{2\cdot 81+44}$$
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