Question

Реши систему уравнений способом алгебраического сложения. z - 4t = 5 3z - 7t = 36​

Answer 1

$\displaystyle\bf\\\left \{ {{z-4t=5 \ |\cdot(-3)} \atop {3z-7t=36}} \right. \\\\\\+\left \{ {{-3z+12t=-15 \ } \atop {3z-7t=36}} \right. \\-----------\\-3z+12t+3z-7t=-15+36\\\\15t=21\\\\t=1,4\\\\z=5+4t=5+4\cdot 1,4=5+5,6=10,6\\\\Otvet \ : (1,4 \ ; \ 10,6)$