1.
(1 1/4×2,6-4)÷1,2+0,3
(1/4×13/5-4)÷6/5+3/10
(13/20-4)÷6/5+3/10
(-67/20)÷6/5+3/10
-67/20×5/6+3/10
-67/4×1/6+3/10
-67/24+3/10
-229/120=2 59/120≈2,49167
2.
0,25+1/12÷(1/3×1,25-9/16)
1/4+1/12÷(1/3×5/4-9/16)
1/4+1/12÷(5/12-9/16)
1/4+1/12÷(-7/48)
1/4-1/12×48/7
1/4-4/7
-9/28≈-0,321429
3.
2/9÷0,8-0,5/1,6×0,25
2/9÷4/5-1/2/0,4
2/9×5/4-1/2/2/5
1/9×5/2-1/2/2/5
5/18-1/2/2/5
-2/9/2/5
2/9-/2/5
-5/9≈-0,555556
4.
2 3/4÷(1 1/2-2/5)+(3/4+5/6)÷3 1/6/(3 1/2÷4 2/3+4 2/3÷3 1/2)×4 4/5
3/2÷(1/2-2/5)+19/12×1/3×1/6/(1/4+4×1/3×1/3)×4×4/5
3/2÷1/10+19/216/(1/4+4/9)×4×4/5
3/2×10+19/216/25/36×4×4/5
3×5+19/216/5/9×4
15+19/216/20/9
3259/216/20/9
3259/480=6 379/480=6,789583
5.
(2/15+712)×30/43-(2÷2 1/2)×5/32/(11 5/11-8 21/22)÷1 2/3
43/60×30/43-(1 1/2)×5/32/(5-4 21/11)÷1 2/3
1/2-1/2×5/32/(5-84/11)÷1 2/3
1/2-5/64/-29/11×2/3
27/64/-58/33
27/64-/58/33
-891/3712≈-0,340032
6.
3/4÷5/6+2 1/2×2/5-1÷1 1/6/((1 1/2)^3-3/4)÷7/8
3/4×6/5+2/5-1 1/6/((1/2)^3-3/4)×8/7
3/2×3/5+2/5-1/6/(1/8-3/4)×8/7
9/10+2/5-1/6/-5/8×8/7
17/15/-5×1/7
17/15/-5/7
17/15-/5/7
-119/75=-1 44/75≈-1,58667
7.
227,36÷(865,6-20,8×40,5)×8,38+1,12
227,36÷(865,6-842,4)×8,38+1,12
227,36÷23,2×8,38+1,12
82,124+1,12
83,244=20811/250=83 61/250