Пошаговое объяснение:
1)x=(2/3)x + 1
x - (2/3)x = 1
(1/3)x = 1
x = 1 : 1/3
x = 3
2) x - 1/2 = (3/4)x
x - (3/4)x = 1/2
(1/4)x = 1/2
x = 1/2 : 1/4
x = 1/2 * 4/1
x = 2
3) x - 2/3 = (5/6)x
x - (5/6)x = 2/3
(1/6)x = 2/3
x = 2/3 : 1/6
x = 2/3 * 6/1
x = 4
4) (1 4/5)y = y + 4.
(1 4/5)y - y = 4
(4/5)y = 4
y = 4 : 4/5
y = 4 * 5/4
y = 5
5) (2/3)y - 1/3 = 5/9y
(2/3)y - (5/9)y = 1/3
(6/9)y - (5/9)y = 1/3
(1/9)y = 1/3
y = 1/3 : 1/9
y = 1/3 * 9/1
y = 3
6)(3/4)y - 2/3 = (7/12)y
(3/4)y - (7/12)y = 2/3
(9/12)y - (7/12)y = 2/3
(1/6)y = 2/3
y = 2/3 : 1/6
y = 2/3 * 6/1
y = 4
а)8 5/7+3,15+1 2/7+4,25=(8 5/7+1 2/7)+(3,15+4,25)=10+7,4=17,4
б)4,7+2/3+1 3/5+3,3=(4,7+3,3)+(2/3+1 3/5)=8+2 4/15=10 4/15
в)8 19/20+5,875+20 35/40=(8 19/20+20 35/40)+5,875=29 33/40+5,875=29 33/40+5 35/40=34 68/40=34 17/10=35,7
г)6,75+3 1/4-7 5/28=(3 1/4-7 5/28)+6,75= -3 13/14+6,75= -3 13/14+6 3/4=2 23/28
д)2,1+1 7/30-(4-2,9)=2,1+1 7/30-1,1=(2,1-1,1)+1 7/30=1+1 7/30=2 7/30
е)22-(4 5/7+8,91+1,09)=22-(4 5/7+10)=22-4 5/7-10=(22-10)-4 5/7=12-4 5/7=7 2/7
ж)76-4 7/25+8,28=(76+8,28)-4 7/25=84,28-4 7/25=84 7/25-4 7/25=80
з)2 5/6-1,6-2/3=(2 5/6-2/3)-1,6=2 1/6-1,6=17/30
(-бесконечность;6)