Question

955 решите уравнение​

Answer 1

Во всех примерах действует такое:

$\frac{a}{b} = \frac{c}{d}$

$a \times d = b \times c$

И такое:

$a \div \frac{b}{c} = a \times \frac{c}{b}$

1)

$\frac{1.7 + 0.1x}{3} = 2$

$1.7 + 0.1x = 2 \times 3$

$1.7 + 0.1x = 6$

$0.1x = 6 - 1.7$

$0.1x = 4.3$

$\frac{1}{10} x = \frac{43}{10}$

$x = \frac{43}{10} \div \frac{1}{10}$

$x = \frac{43}{10} \times \frac{1}{10}$

$x = \frac{43}{1}$

$x = 43$

2)

$\frac{15.8 - 0.01x}{4} = 3$

$15.8 - 0.01x = 3 \times 4$

$15.8 - 0.01x = 12$

$- 0.01x = 12 - 15.8$

$- 0.01x = - 3.8$

$x = - 3.8 \div ( - 0.01)$

$x = - \frac{38}{10} \div ( - \frac{1}{100} )$

$x = - \frac{38}{10} \times ( - \frac{100}{1} )$

$x = \frac{38 \times 100}{10}$

$x = 380$

3)

$\frac{16.3 - 100x}{2} = 5$

$16.3 - 100x = 10$

$- 100x = 10 - 16.3$

$- 100x = - 6.3$

$x = - 6.3 \div ( - 100)$

$x = - \frac{63}{10} \div ( - 100)$

$x = - \frac{63}{10} \times ( - \frac{1}{100} )$

$x = \frac{63}{1000}$

$x = 0.063$

4)

$\frac{100x + 4.6}{5} = 3$

$100x + 4.6 = 3 \times 5$

$100x + 4.6 = 15$

$100x = 15 - 4.6$

$100x = 10.4$

$x = 10.4 \div 100$

$x = \frac{104}{10} \div \frac{100}{1}$

$x = \frac{104}{10} \times \frac{1}{100}$

$x = \frac{104}{1000}$

$x = 0.104$