Răspuns:
1. 412
2. 100
3. 4
4a. 70
Explicație pas cu pas:
1. 663+357-608=412
2. a(b+c) =4*25=100
3. a(b+c)=36
a*9=36
a=36/9
a=4
4 a) 7(13-3)=7*10=70
b) 2009(2008-2006)-2*2008=
=2009*3-2*2008=
=6027-4016=2011
c) 96(94-92)-2*93=
=96*2-2*93=
=192-186=6
d) (5+17)* 4+44=22*4+44=88+44=132