Как думаете, сколько я весил при росте 123 см в 5,5 лет?

1. -10y-64=-6y; -10y+6y=64; -4y=64; y=64/(-4)=-16;
2. 9m-8=6m+7; 9m-6m=8+7; 3m=15; m=15/3=5;
3. 6x+10=5x+15; 6x-5x=15-10; x=5;
4. 16m-5=15m-10; 16m-15m=5-10; m=-5;
5. 8-5n=10-4n; 4n-5n=10-8; -n=2; n=-2;
6. 18=3y+3; 18-3=3y; 15=3y; y=15/3=5;
7. 40-12x=20-11x; 40-20=12x-11x; x=20;
8. -5n-16=3n; 3n+5n=-16; 8n=-16; n=-16/8=-2;
9. 25=5y-5; 5y=25+5; 5y=30; y=30/5=6;
10. 25-9y=5y+11; 25-11=5y+9y; 14=14y; y=14/14=1;
11. 63-8n=n; 63=n+8n; 9n=63; n=63/9=9;
12. 28-9m=-8-10m; 28+8=9m-10m; 36=-m; m=-36;
13. 4y+7=5y+4; 4y-5y=4-7; -y=-3; y=3;
14. 56-9n=-5n; 56=9n-5n; 56=4n; n=56/4=14

1)

2 1/2*(2/15-3 5/6)-2 3/4 = -12,  

1. 2/15-3 5/6 = 2/15-23/6 = 4/30-115/30 = -111/30 = - 37/10 = - 3 7/10,

2. 2 1/2 * (- 3 7/10) = - 5/2 * 37/10 = - 37/4 = - 9 1/4,

3. - 9 1/4 - 2 3/4 = - 11 4/4 = - 12,

2)

-1 1/7*(4/5+19/20)*(6 5/6+4 2/3) = - 23 1/3,

1. 4/5+19/20 = 16/20+19/20 = 35/20 = 7/4 = 1 3/4,

2. -1 1/7 * 1 3/4 = - 8/7 * 7/4 = - 8/4 = - 2,

3. 6 5/6 + 4 2/3 = 6 5/6 + 4 4/6 = 10 10/6 = 11 4/6 = 11 2/3,

4. -2 * 11 2/3 = -2 * 35/3 = - 70/3 = - 23 1/3,

3)

(6 3/8-2 3/4)*(-4)+7/18×9 = - 11,

1. 6 3/8 - 2 3/4 = 6 3/8 - 2 6/8 = 5 11/8 - 2 6/8 = 3 5/8,

2. 3 5/8 * (-4) = - 29/8 * 4 = - 29/2 = - 14 1/2,

3. 7/18 * 9 = 7/2 = 3 1/2,

4. - 14 1/2 + 3 1/2 = - 11,

4)

9 1/6:(4 1/3-8)+24*3/8 = 6 1/2,

1. 4 1/3 - 8 = 4 1/3 - 7 3/3 = - 3 2/3,

2. 9 1/6 : (- 3 2/3) = - 55/6 : 11/3 = - 55/6 * 3/11 = - 5/2 = - 2 1/2,

3. 24 * 3/8 = 3 * 3 = 9,

4. - 2 1/2 + 9 = - 2 1/2 + 8 2/2 = 6 1/2

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