Sagot :
A = 8/9 − 13/25 ÷ (−1/25)
= 8/9 + 13/25 × 25/1
= 8/9 + 13
= 8/9 + 117/9
= 125/9
B = (−11/28) ÷ (−1/21) − 1/4
= 11/28 × 21/1 − 1/4
= 231/28 − 7/28
= 224/28
= 8
C = 15/2 + (−14/27) ÷ 4/21
= 15/2 − 14/27 × 21/4
= 15/2 − 7/27 × 21/2
= 405/54 − 147/54
= 258/54
= 43/9
D = −1/10 − (3/20 + −1/2)
= −1/10 − (3/20 − 10/20)
= − 2/20 − 3/20 + 10/20
= −2/20 + 7/20
= 5/20
= 1/4
E = 13/18 + (−4/3) × (−11/4)
= 13/18 + 11/3
= 13/18 + 66/18
= 79/18
F = 13/20 − (10/3 + −1/3)
= 13/20 − 3
= 13/20 − 60/20
= −47/20