a)12x10:4+(190-30):8+(202:2+33x3):100=
120:4+160:8+(101+99):100=
30+20+200:100=
50+2=52
b. (9x7+7x8)x4-(404:4+44:4):2=
(63+56)x4-(101+11):2=
119x4-112:2=
476-56=420
c.1000-(250:2+25x3)x3-(25+15x5)x4=
1000-(125+75)x3-(25+75)x4=
1000-200x3-100x4=
1000-600-400=
400-400=0
d. 23x(157-24x6)-477:3-(22+220:2)=
23x(157-144)-159-(22+110)=
23x13-159-132=
299-159-132=
140-132=8
e. 135+5000:(1385-385)+3x(40+8:2) =
135+5000:1000+3x(40+4) =
135+5+3x44=
140+132=272
