Răspuns:
a)579+3045=3624
b)2021-439=1582
c)506+885=1391
d)145+20+[107+83-(405-18•16)]=
=145+20+[107+83-(405-288)]=
=145+20+(107+83-177)=
=145+20+(190-177)=
=145+20+13=
=165+13=
=178
e)1+2+3+...+107
=107×(107+1):2=
=107×108:2=
=11.556:2=
=5.778
f)4+7+10+...+73
=73×(73+1):2
=73×74:2
=5.402:2
=2.701
Explicație pas cu pas:
Sper că te- am ajutat ☆●•°