Bonsoir,

17)

A = 5 x 2/3

A = 10/3

B = - 7/5 x 4

B = - 28/5

C = 5/6 x - 11/4

C = - 55/30

C = (5 x - 11) / (5 x 6)

C = - 11/6

D = - 8/9 x - 10/9

D = 80/81

18)

A = 8/7 x 2/9 = 16/63

B = - 5 x 4/9 = - 20/9

19)

A = - 5/9 x - 2/17 = +

B = 2/- 9 x - 2/- 5 = - 2/9 x 2/5 = -

C = - - 4/5 x - 3/25 = 4/25 x - 3/25 = -

D = - 1/- 7 x - 2/- 5 = 1/7 x 2/5 = +.