Question

Памагите училка бьет уже!

Answer 1

$\left \{ {{\frac{z+t}{15}*15-\frac{z-t}{3}*15=1*15} \atop {\frac{2z-t}{6}*6-\frac{3z+2t}{3}*6}=-25*6} \right. \\\\\\\left \{ {{z+t-5z+5t=15} \atop {2z-t-6z-4t=-150}} \right.\\\\\\\left \{ {{-4z+6t=15} \atop {-4z-5t=-150}|*(-1)} \right.\\\\\\+\left \{ {{-4z+6t=15} \atop {4z+5t=150}} \right.\\-------\\ 11t=165\\\\t=15\\\\4z=6t-15=6*15-15=90-15=75\\\\z=18,75\\\\Otvet:\boxed{z=18,75;t=15}$