Sagot :
a) 3/8 + 11/8 b) -2/9 + 8/9 c) 3/16 - -7/16
= 14/8 = 6/9 = 10/16
= 7/4 = 2/3 = 5/8
d) 5/12 + 5/3 e) 3/7 - 8/21 f) -5/3 - 2/15
= 5/12 + 5x4/3x4 = 3x3/7x3 - 8/21 = -5x5/3x5 - 2/15
= 5/12 + 20/12 = 9/21 - 8/21 = -25/15 - 2/15
= 25/12 = 1/21 = -27/15
= -9/5
= 14/8 = 6/9 = 10/16
= 7/4 = 2/3 = 5/8
d) 5/12 + 5/3 e) 3/7 - 8/21 f) -5/3 - 2/15
= 5/12 + 5x4/3x4 = 3x3/7x3 - 8/21 = -5x5/3x5 - 2/15
= 5/12 + 20/12 = 9/21 - 8/21 = -25/15 - 2/15
= 25/12 = 1/21 = -27/15
= -9/5