Question

упростите выражение​

Answer 1

$\dfrac{y-9}{y-8}*\dfrac{y^2-64}{y^2-16y+64} = \dfrac{y-9}{y-8}*\dfrac{(y-8)(y+8)}{(y-8)^2} = \dfrac{y-9}{y-8}*\dfrac{y+8}{y-8} =\\\\\\= \dfrac{x-9+y+8}{y-8} = \dfrac{2y-1}{y-8}$