Tính giá trị biểu thức một cách hợp lí

1) $B=\left(5-\frac{3}{4}+\frac{1}{5}\right)-\left(6+\frac{7}{4}-\frac{8}{5}\right)-\left(2-\frac{5}{4}+\frac{16}{5}\right)$

2)  $C=\left(-\frac{2}{3}+1\right)-\left(\frac{7}{5}-0,2\right)+\left(\frac{7}{15}-1+\frac{4}{3}\right)$

3)  $D=-0,25-\left(\frac{-3}{4}\right)-\left[-\frac{7}{3}+\left(\frac{-9}{2}\right)\right]-\frac{5}{6}$

4) $E=\left[1-\left(\frac{2}{5}-\frac{4}{3}\right)\right]-\left[\left(0,8-1\right)-\left(1,4+2\right)\right]$

1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21 * 22 * 23 * 24 * 25 * 26 * 27 * 28 * 29 * 30 * 31 * 32 * 33 * 34 * 35 * 36 * 37 * 38 * 39 * 40 * 41 * 42 * 43 * 44 * 45 * 46 * 47 * 48 * 49 * 50 * 51 * 52 * 53 * 54 * 55 * 56 * 57 * 58 * 59 * 60 * 61 * 62 * 63 * 64 * 65 * 66 * 67 * 68 * 69 * 70 * 71 * 72 * 73 * 74 * 75 * 76 * 77 * 78 * 79 * 80 * 81 * 82 * 83 * 84 * 85 * 86 * 87 * 88 * 89 * 90 * 91 * 92 * 93 * 94 * 95 * 96 * 97 * 98 * 99 * 100 bằng bao nhiêu?