Bonjour,
A+B
-3/27 +2/3
= -1/ 9 +2/3
= -1/9 +6/9
= 5/9
C-D
9/8 - 5/6
= 27/24 - 20/24
= 7/24
A*C
-3/27 * 9/8
= - 1/9 * 9/8
= -9/72
= -1/ 8
B/D
= 2/3 * 6/5
= 12/15
= 4/5
(A-B/C +D) *15
= (-3/27 - 2/3* 8/9 + 5/6) * 15
= (- 3/27 -16/27 + 5/6) *15
= (-19/27 +5/6)*15
= -285/27 + 75/6
= -95/9 +25/2
= - 190/18 + 25/18
= -165/18
= - 55/6
