Question

cum se calculeaza 3*a+7*b+4*c stiind ca a+b=20 si b+c=30

Answer 1

a+b=20⇒3a+3b=60
b+c=30⇒4b+4c=120
Adunam: 3a+(3b+4b)+4c=60+120
               3a+7b+4c=180
R:180
Sper ca te-am ajutat.

Answer 2

3a +3b=3*20=60. 4b+4c=4*30=120. 3a+3b+4b+4c=60+120. 3a+7b+4c=180 Sper ca te-am ajutat:)))