(3x-10y^2)/(2y-3)+5y+(2x-13y)/(3-2y) при y=-3.5 x=14 (m^2-n)/(m-7)-m-(6m)/(7-m) при m=2...

= $\frac{3x-10y^{2} }{2y-3}- \frac{2x-13y}{2y-3}+5y= \frac{3x-2x-10y^{2}+13y }{2y-3} + \frac{5y(2y-3)}{2y-3}=$ $\frac{x-10y^{2}+13y +10 y^{2}-15y }{2y-3}=$ $\frac{x-2y }{2y-3}$
$\frac{14-2*(-3.5)}{2*(-3.5)-3}= \frac{14+7}{-10.5}= -\frac{21}{10.5}=-2$

$(m^2-n)/(m-7)-m-(6m)/(7-m)= \frac{ m^2- n+6m}{m-7}-m=$ $\frac{ m^2- n+6m-m ^{2}+7m }{m-7}= \frac{13m-n}{m-7} = \frac{13*2+4}{13-7}= \frac{30}{6}=5$