Question

pune paranteze pentru a obtine propozitiile adevarate :

a} 3x1+2x4+1=30
b} 3x1+2x4+1=37
c} 3x1+2x4+1=28
d} 3x1+2x4+1=21

Answer 1

3x(1+2x4)+1=3x9+1=28:
3x(1+2)x4+1=3x3x4+1=9x4+1=37
(3x1+2)x4+1=(3+2)x4+1=5x4+1=21
3x(1+2x4+1)=3x(1+8+1)=3x10=30

Answer 2

a) 3x(1+2x4+1)=30
b) 3x(1+2)x4+1=37
c) 3x(1+2x4)+1=28
d) (3x1+2)x4+1=21