Bonsoir,
a) 8 + 5/4
= 8/1 + 5/4
= 32/4 + 5/4
= 37/4
b) (17-15)/(3+2)
= 2/5
c) 17 - 15/3 + 2
= 17 - 5 + 2
= 17 + 2 - 5
= 19 - 5
= 14
d) 8/(5+4)
= 8/9
e) 17*((15*4)/(3-2)) + 2*8
= 17*(60/1) + 2*8
= 17*60 + 2*8
= 1 020 + 16
= 1 036
f) (15+4)/(13-3) - 0,3*10
= 19/10 - 0,3*10
= 19/10 - 3
= 19/10 - 3/1
= 19/10 - 30/10
= - 11/10