Question

Решите пожалуйста 1348

Answer 1

$a) \frac{4.6}{x + 4.4} = \frac{8.4}{3x + 5.1} \\ \\ \\ 4.6(3x + 5.1) = 8.4(x + 4.4) \\ \\ 13.8x + 23.46 = 8.4x + 36.96 \\ \\ 13.8x - 8.4x = 36.96 - 23.46 \\ \\ 5.4x = 13.5 \\ \\ x = 13.5 \div 5.4 = 135 \div 54 \\ \\ x = 2.5$
Ответ: х=2,5







$b) \frac{2 \frac{2}{3} }{x + \frac{1}{3} } = \frac{1 \frac{1}{2} }{x - 1 \frac{1}{8} } \\ \\ \frac{ \frac{8}{3} }{x + \frac{1}{3} } = \frac{\frac{3}{2} }{x - \frac{9}{8} } \\ \\ \frac{8}{3} (x - \frac{9}{8} ) = \frac{3}{2} (x + \frac{1}{3} ) \\ \\ \frac{8}{3} x - 3 = \frac{3}{2} x + \frac{1}{2} \\ \\ \frac{8}{3} x - \frac{3}{2} x = \frac{1}{2} + 3 \\ \\ \frac{8 \times 2}{3 \times 2} x - \frac{3 \times 3}{2 \times 3}x = \frac{1}{2} + \frac{3}{1} \\ \\ \frac{16}{6} x - \frac{9}{6} x = \frac{1}{2} + \frac{3 \times 2}{1 \times 2} \\ \\ \frac{7}{6} x = \frac{1}{2} + \frac{6}{2} \\ \\ \frac{7}{6} x = \frac{7}{2}$
$x = \frac{7}{2} \div \frac{7}{6} = \frac{7}{2} \times \frac{6}{7} \\ \\ \\ x = 3$
Ответ : х= 3



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