1. 4/15+3=y+153/45 49/15=y+17/5
-y=17/5-49/15 -y=2/15 y=-2/15
2. 8x/9+1=-1 8x+9=-27 8x=-27-9 8x=36 x=-9/2
3. (b+4)-1=-3 b+4-1=-3 b+3=-3 b=-3-3 b=-6
4. 12 * (1 3/4х + 5/8) = - 6 1/21 3/4х + 5/8 = - 6 1/2 : 12 7/4х + 5/8 = -13/2 * 1/12 7/4х + 5/8 = - 13/24 7/4х = - 13/24 - 5/8 7/4х = - 13/24 - 15/24 7/4х = - 28/24 х = - 28/24 : 7/4 х = - 28/24 * 4/7 х = - 28*4/24*7 х = - 4*4/24 х = - 16/24 х = - 2/3проверка: 12 * (1 3/4 * (- 2/3) + 5/8) = - 6 1/2 12 * (- 7/4 * 2/3 + 5/8) = - 13/2 12 * (- 14/12 + 5/8) = - 13/2 12 * (- 84/72 + 45/72) = - 13/2 12 * (- 39/72) = - 13/2 - 39*12/72 = - 13/2 - 39/6 = - 13/2 - 13/2 = - 13/2
5. 3x-2/4+2x+3/2-2,5+2=0
2,5x+3=0 2,5x=-3 x=-1/2