Question

только 2 и 4 .......​

Answer 1

$\dfrac{2}{3}x + \dfrac{4}{5}y = \dfrac{2}{3}\cdot9 + \dfrac{4}{5}\cdot(-10) = 6 - 8 = -2$

$\dfrac{a+3c}{2a-c} = \dfrac{3 + 3\cdot(-1)}{2\cdot3 - (-1)} = \dfrac{0}{7} = 0$

Answer 2

Ответ:

Объяснение:

(2*9)/3-(4*10)/5=6-8=-2

(3 - 1*3)/(2*3+1)=0/7=0