Question

$frac{4-y^{ frac{2}{7}} }{2+ y^{ frac{1}{7}} } -2$

Answer 1

$frac{4-y^ frac{2}{7} }{2+y^ frac{1}{7} } -2= frac{2^2-(y^ frac{1}{7})^2 }{2+y^ frac{1}{7} } -2= \ = frac{(2-y^ frac{1}{7})(2+y^ frac{1}{7}) }{2+y^ frac{1}{7} } -2=2-y^ frac{1}{7} -2=y^ frac{1}{7}$