Sagot :
A )
7a - (3b - 2c)
= 7 x 8 - (3 x 5 - 2 x 6)
= 56 - ( 15 - 12 )
= 56 - 3
= 53
B)
6a + 2c - ab
= 6 x 8 + 2 x 6 - 8 x 5
= 48 + 12 - 40
= 60 - 40
= 20
7a - (3b - 2c)
= 7 x 8 - (3 x 5 - 2 x 6)
= 56 - ( 15 - 12 )
= 56 - 3
= 53
B)
6a + 2c - ab
= 6 x 8 + 2 x 6 - 8 x 5
= 48 + 12 - 40
= 60 - 40
= 20