Sagot :
Explications étape par étape
a. 4/5 - ( 7/10 - 5/6 )
= 24/30 - ( 21/30 - 25/30 )
= 24/30 - ( - 4/30 )
= 24/30 + 4/30
= 28/30
= 14/15
b. 9/5 + ( - 3/7 )
= 9/5 - 3/7
= 63/35 - 15/35
= 48/35
Explications étape par étape
a. 4/5 - ( 7/10 - 5/6 )
= 24/30 - ( 21/30 - 25/30 )
= 24/30 - ( - 4/30 )
= 24/30 + 4/30
= 28/30
= 14/15
b. 9/5 + ( - 3/7 )
= 9/5 - 3/7
= 63/35 - 15/35
= 48/35