Răspuns:
4. a) x=1635
b) x=287
c) x=1569
5. a=6
Explicație pas cu pas:
a) x+3487=5122 => x=5122-3487 => x=1635
b) x+522-389=420
x+522=420+389
x+522=809
x=809-522
x=287
c) 4435-x=2866
x=4435-2866
x=1569
5. x=9
a=3x+3*(2x-10)-5x
a=3*9+3*(2*9-10)-5*9
a=27+3*(18-10)-45
a=27+3*8-45
a=27+24-45
a=51-45
a=6
