Question

дууууууууууужееееее ПРОШУ 20б❗
1) 2x = 15-x;
2) 0,3x = 3,9-x;
3) 7x + 1 = 25-x;
4) 52(x-1)=4-x;
5) 0,2(3x-4)= 1,6(x - 2);
6)2/3(1/3x-1/2=4(x+5/8)​

Answer 1

1) Ответ: 5

$2x = 15 - x \\ 2x + x = 15 \\ 3x = 15 \\ x = 5$

2) Ответ: 3

$0.3x = 3.9 - x \\ 0.3x + x = 3.9 \\ 1.3x = 3.9 \\ x = 3$

3) Ответ: 3

$7x + 1 = 25 - x \\ 7x + x = 25 - 1 \\ 8x = 24 \\ x = 3$

4) Ответ: 2

$5 -2(x - 1) = 4 - x \\ 5 - 2x + 1 = 4 - x \\ - 2x + x = 4 - 1 - 5 \\ - x = - 2 \\ x = 2$

5) Ответ: 2,4

$0.2(3x - 4) = 1.6(x - 2) \\ 0.6x - 0.8 = 1.6x - 3.2 \\ 0.6x - 1.6x = - 3.2 + 0.8 \\ - x = - 2.4 \\ x = 2.4$

6)

$\frac{2}{3} ( \frac{1}{3} x - \frac{1}{2} ) = 4(x + \frac{5}{8} ) \\ \frac{2}{9} x - 3 = 4x + \frac{5}{2} \\ \frac{2}{9} x - 4x = \frac{5}{2} + 3 \\ \frac{2}{9} x - 3 \frac{9}{9} x = 3 \frac{5}{2} \\ - 3 \frac{7}{9} x = 5 \frac{1}{2} \\ x = 5 \frac{1}{2} \div ( - 3 \frac{7}{9} ) = \frac{11}{2} \div \frac{34}{9} = \frac{11}{2} \times \frac{9}{34} \\ x = \frac{99}{68} = 1 \frac{31}{68}$