Question

$(4x^{2} -25y^{2}) * ( frac{1}{2x+5y} + frac{1}{2x-5y})$

Answer 1

$(4 x^{2} -25 y^{2} )*( frac{2}{4 x^{2} -25y^{2} } )=2$

Answer 2

(2x-5y)(2x+5y)*(2x-5y+2x+5y)/(2x-5y)(2x+5y)=4x