Question

. Алгебра 7 класс уравнения . ​

Answer 1

Ответ:

Объяснение:

а) $\frac{12}{x}$ = $\frac{2,5}{12,5}$ = $\frac{12 . 12,5}{x . 2,5}$ = $\frac{150}{x . 2,5}$ х = 150:2,5 х= 60

б) 10х-(7х+8) = 12        

10х-7х-8 = 12

3х-8 = 12

3х = 12+8

3х = 20

х = 20:3

х = $\frac{20}{3}$

в) $\frac{2x}{7}$ = $\frac{5-x}{14}$ = $\frac{2x . 14}{5-x . 7}$ = $\frac{2x . 7}{5-x}$

г) 3. $\frac{4-2x}{3}$ = 4х

36-18х = 4х

-18х-4х = -36

-22х = -36

х = $\frac{36}{22}$    х = $\frac{18}{11}$

д) $\frac{3-4x}{2}$ . $\frac{x-1}{3}$ = 0

$\frac{(3-4x) . 3}{2 . (x-1)}$ = -0

$\frac{9-12x}{2x-2}$ = 0

$\frac{9-6x}{-2}$ = 0

9-6х : -2 = 0

3. (3-2х) : -2 = 0

(3-2х) : -2 = -3

(3-2х) = -3 . -2

(3-2х) = 6

3-2х = 6

-2х = 6-3

-2х = 3

х = 3: -2

х = -  $\frac{3}{2}$