Question

Daca a+b=72 si b+c=98 . Calculati 3a+8b+5c

Answer 1

3a+8b+5c=3a+3b+5b+5c=3(a+b) +5(b+c)=3*72+5*98=216+490=706

Answer 2

3a+8b+5c=3a+3b+5b+5c=
=3(a+b)+5(b+c)=
=3×72+5×98=
=216+490=
=706;