Question

Stiind ca a=5 si b+c=12, calculati:
ab+ac=
2a+4b+4c=
10a-4(b+c)=
6b-5a+6c=
8b+8c-10c=
12(b+c)-20a=
Ajutatima va rog!!

Answer 1

Stiind ca a=5 si b+c=12, calculati:ab+ac=a(b+c)=5·12=60
2a+4b+4c=2a+4(b+c)=2·5+4·12=10+48=58
10a-4(b+c)=10·5-4·12=50-48=2
6b-5a+6c=6b+6c-5a=6(b+c)-5a=6·12-5·5=72-25=47
8b+8c-10c=?
12(b+c)-20a=12·12-20·5=144-100=44