## anonymous 5 years ago Add. Simplify by removing factors of 1if possible 28zx + z-7x ----- ----- z^2-49x^2 z+7x

First factor bottom (z-7x)(z+7x) This shares the (z+7x) in other denominator so common denominator will be (z-7x)(z+7x) multiply 2nd fraction by (z-7x) on top and bottom $=\frac{28xz +(z-7x)(z-7x)}{(z-7x)(z+7x)}$ expand the top and add like terms $=\frac{z^{2} + 49x^{2}}{(z-7x)(z+7x)}$ top will not factor so this is answer