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.
1)(.)B-(.)A=2-(-3)=2+3=5 ед.отр. 2)(-1)-(-5)=-1+5=4 ед.отр. 4)(-7)-(-4)=-7+4=-3 3ед.отр.
3)0-(-2)=0+2=2 ед.отр.