Question

14. Rezolvați ecuațiile in N :
a) 4(x+3)+15(x+1)=3(2x+3)+7(x+4)+8
b) 5(2x-3+4(4x+7)-48=3(2x+1)+4(x+3)+30

Answer 1

a) 4(x+3)+15(x+1)=3(2x+3)+7(x+4)+8
Dam factor comun x.
x×(4+15)+4×3+15×1=x×(3×2+7)+3×3+7×4+8
x×19+12+15=x×13+9+28+8
x×19+27=x×13+45
x×19=x×13+18
x×6=18
Impartim prin 6.
x=3

b) 5(2x-3)+4(4x+7)-48=3(2x+1)+4(x+3)+30
Dam factor comun x.
x×(2×5+4×4)-5×3+7×4-48=x×(3×2+4)+3×1+3×4+30
x×26-15+28-48=x×10+3+12+30
x×26-35=x×10+45
x×26=x×10+80
x×16=80
Impartim prin 16.
x=5