2. Решите уравнение: a) 3,4y + 0,65 = 0,9y - 25,6; б) 1
3 : 59 = x : 4,7.

Решение:

а)

1. \[ 3.4y + 0.65 = 0.9y - 25.6 \]
2. \[ 3.4y - 0.9y = -25.6 - 0.65 \]
3. \[ 2.5y = -26.25 \]
4. \[ y = \frac{-26.25}{2.5} \]
5. \[ y = -10.5 \]

б)

1. \[ 1\frac{1}{3} \div 5\frac{2}{9} = x \div 4.7 \]
2. \[ \frac{4}{3} \div \frac{47}{9} = x \div \frac{47}{10} \]
3. \[ \frac{4}{3} \times \frac{9}{47} = x \div \frac{47}{10} \]
4. \[ \frac{12}{47} = x \times \frac{10}{47} \]
5. \[ x = \frac{12}{47} \times \frac{47}{10} \]
6. \[ x = \frac{12}{10} \]
7. \[ x = 1.2 \]

Ответ: а) -10,5; б) 1,2