Question

дам 25 баллов! заранее спасибо

Answer 1

Ответ:

7.4

Пошаговое объяснение:

$\frac{5}{12} (4.8x-1\frac{1}{5}y) - 5.4(\frac{4}{9} x + 1.5y);\\\frac{5}{12}(\frac{48}{10} x-\frac{6}{5} y)-\frac{54}{10}(\frac{4}{9} x + \frac{15}{10} y;)\\\frac{5*48}{12*10}x -\frac{5*6}{12*5} y-\frac{54*4}{10*9} x-\frac{54*15}{10*10}y; \\\frac{240}{120}x -\frac{30}{60} y-\frac{216}{90} x-\frac{810}{100}y; \\2x -0.5 y-2.4 x-8.1y; \\-0.4x-8.6y = -0.4(x + 21.5y)$

Подставим значения:

$-0.4(4+21.5(-1\frac{2}{43});\\-1.6 + \frac{86}{10} * \frac{45}{43} ;\\-\frac{16}{10} +\frac{86*45}{10*43} ;\\-\frac{16}{10} +\frac{2*45}{10} ;\\\frac{90-16}{10} = \frac{74}{10} = 7.4$