Bonjour,
a)
( -7/50)( 3/3) + (2/75)( 2/2)=
-21/150 + 4/150 = -17/150
b)
1/5 * 3/3 - 2/3 * 5/5=
3/15 - 10/15 = -7/15
c)
1/12 * 3/3 - 1/9 * 4/4=
3/36 - 4/36 = -1/36
d)
4/18 * 6/6 + 5/27 * 4/4=
24/108 + 20/ 108 = 44/108 = 22/54= 11/27
