Question

Решите уравнения: а) - 3,1 + 1/6 x = - 3,5 б) ( 5,6 - 2x) × x = 0 выполните действия: а) ( 1,25 - 1 1/3) × (-5/7) - 1 1/6 : 5 4/9 б) - 2,75 × (-0,1)^2 × (- 3 7/11)

Answer 1

-3.1 + 1/6x = -3.5
1/6x = -3.5 + 3.1
1/6x = -0.4
x = -0.4 : 1/6
x = -0.4 * 6
x = -2.4
=================
(5.6 - 2x) * x = 0
x _1=0
5.6 - 2x = 0
-2x = -5.6
2x = 5.6
x = 5.6/2
x=2.8
=================
$\\(1.25 - 1\frac{1}{3}) * (-\frac{5}{7}) - 1\frac{1}{6} : 5 \frac{4}{9} = \\ \\1.25 - 1\frac{1}{3} = 1\frac{1}{4} - 1 \frac{1}{3} = 1\frac{3}{12} - 1\frac{4}{12} = -\frac{1}{12}\\ \\-\frac{1}{12} * (-\frac{5}{7}) = \frac{5}{12*7} = \frac{5}{84} \\ \\1\frac{1}{6} : 5 \frac{4}{9} = \frac{7}{6} : \frac{49}{9} = \frac{7}{6} * \frac{9}{49} = \frac{1}{2} * \frac{3}{7} = \frac{3}{14} \\ \\ \frac{5}{84} - \frac{3}{14} = \frac{5}{84} - \frac{18}{84} =- \frac{13}{84}\\$
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 - 2,75 × (-0,1)^2 × (- 3 7/11)  = -2.7 * (-0.01) * (-3  7/11) = 0.027 * (-3  7/11) = 0.027 * (-40/11) = -1.08/11 = -108/1100