78 lei a cheltuit a treia zi
78:2=39 lei a cheltuit a doua zi
39+10 =49 lei a cheltuit in prima zi
3)
(b-5)x2=30
b-5=30:2
b-5=15
b=15+5
b=20
(c-17)x3+15=45
(c-17)x3=45-15
c-17=30:3
c-17=10
c=10+17
c=27
(2x(d-30)-45)x3=165
2x(d-30)-45=165:3
2x(d-30)=55+45
d-30=100:2
d-30=50
d=50+30
d=80
5)
a-a:5=36 l x5
5xa-a=5x36
4a=180
a=180:4
a=45 numarul la care s-a gandit Bogdan