Question

будь ласка поможіть даю 30 балів

Answer 1

$- 0.77 \times \frac{3}{4} + \frac{3}{4} \times 2.81 = \frac{3}{4} \times ( - 0.77 + 2.81) = \frac{3}{4} \times 2.04 = \frac{3 \times 51}{4 \times 25} = \frac{153}{100} = 1.53$

$- 6a \times 1.5b = - 9ab$

$13a + 3.5b - 41a - 1.9b = 1.6b - 28a$

$- 7(x - 4 ) + 3(x - 8) = - 7x + 28 + 3x - 24 = 4 - 4x$

$- 7x = 11 \\ x = - \frac{11}{7} \\ x = - 1 \frac{4}{7}$

$x \div \frac{3}{8} = 1.6 \\ x = 1.6 \times \frac{3}{8} \\ x = \frac{8 \times 3}{5 \times 8} \\ x = \frac{3}{5} \\ x = 0.6$

$- 8 \frac{2}{5} \times x = \frac{21}{25} \\ x = \frac{21}{25} \div ( - 8 \frac{2}{5} ) \\ x = - \frac{21 \times 5}{25 \times 42} \\ x = - \frac{1}{10} \\ x = - 0.1$

$- 6x + 5x - 7x = - 1.92 \\ - 8x = - 1.92 \\ x = - 1.92 \div ( - 8) \\ x = 0.24$

$6x - (3x - 9y) = 6x - 3x + 9y = 3x + 9y = 3 \times 0.8 + 9 \times ( - 1.3) = 2.4 - 11.7 = - 9.3$