Пошаговое объяснение:
8 1/4: 1 1/10-(3- 2 4/5*3/7)=7,5
1. 2 4/5*3/7= 14/5*3/7=14*3/2*7=6/2=3 (14 и 7 сократили на 2)
2. 3-3=0
3. 8 1/4:1 1/10= 33/4:11/10=33*10/4*11=330/44=7,5
4. 7,5-0=7,5
(4 1/6:3 1/3*1/5+5/6)*3=3 1/4
1. 25/6:10/3=25*3/6*10=75/60=5/4 (сократили на 15)
2. 5/4*1/5=5*1/4*5= 1/4 (на 5 сократили)
3. 1/4+5/6= 1*6/24+5*4/24=6/24+20/24=26/24=1 1/12
4. 1 1/12*3= 13/12*3=39/12=3 1/4
3 4/5:9 1/2 +3 9/10:1 1/2-1 5/8=1 3/8
1. 3 4/5:9 1/2 =19/5:19/2=19*2/5*19=2/5
2. 3 9/10:1 1/2= 39/10:3/2=39*2/10*3=26/10=13/5=2 3/5
3. 2/5+2 3/5=2 5/5=3
4. 3-1 5/8= 1 8/8-5/8=1 3/8
20-19 1/2*2/3* (3/4-3/5)=18 1/20
1. 3/4-3/5=3*5/20-3*4/20=(15-12)/20=3/20
2. 19 1/2*2/3= 39/2*2/3= 39*2/2*3=13*2/2=26/2=13
3. 13*3/20=39/20=1 19/20
4.20- 1 19/20=18 20/20=19/20=18 1/20
{13a + 142 = 12b
{(6bd/3) + 34 = 4222910
{12ad = 3620908 - 1300
{12b - 13a = 142
{2bd = 4222910 - 34
{ a = 3619608/12d
{ 12b - 13a =142
{ b = 4222876/2d
{a = 301634/d
{12b - 13a = 142
{b = 2111438/d
12 * (2111438/d ) - 13 * (301634/d) = 142 |*d
25337256 - 3921242 = 142d
21416014 = 142d
d= 21416014/142
d=150817
a = 301634/150817
a= 2
b=2111438/150817
b= 14