Question

в) y-3 1-y г) a²-4 2+a²
------ + ------- = ? ------- - -------- =?
9y 2y 3a 12a

Answer 1

в) $frac{y-3}{9y}+ frac{1-y}{2y}= frac{2*(y-3)+9(1-y)}{18y}= frac{2y-6+9-9y}{18y}= frac{3-7y}{18y}$

г) $frac{a^{2} -4}{3a}- frac{2+ a^{2} }{12a}= frac{4*(a^{2} -4)-(2+ a^{2} )}{12a}= frac{4 a^{2} -16-2- a^{2} }{12a}= frac{3 a^{2} -18}{12a} = frac{3*( a^{2} -6)}{12a}=$$frac{ a^{2} -6}{4a}$