Решить уравнения: 1) 0,6 - 1,6(х-4)=3(7-0,4х) 2) 3/4 (1/2х+2/5)=3х+ 2 целых 1/14

Question

Решить уравнения:

1) 0,6 - 1,6(х-4)=3(7-0,4х)

2) 3/4 (1/2х+2/5)=3х+ 2 целых 1/14

Answer 1

1)0,6- 1,6*(х-4)= 3*(7-0,4х)

0,6-1,6х+6,4 = 21-1,2х

-1,6х+1,2х = -0,6-6,4+21

-0,4х = 14

х = 14:(-0,4)

х =-35

0,6-1,6*(-35-4) = 3*(7-0,4*(-35))

0,6+62,4 = 3*21 = 63

Ответ: -35.

 

2) 3/4*(1/2х+2/5)=3х+2 1/14

 3/8х+3/10 = 3х+2 1/14

3/8х-3х = 2 1/14-3/10

3/8х -2 8/8х = 29/14-3/10

-2 5/8х = 290/140-42/140

-21/8х = 248/140 

-21/8х = 62/35

х = 62/35:(-21/8)

х = 62/35*(-8/21)

х = - 496/735

3/4*(1/2*(-496/735)+2/5) = 3*(-496/735)+2 1/14

3/4*(-248/735+294/735) = -496/245+29/14

3/4*46/735 = -992/490+1015/490 = 23/490

Ответ: -496/735.