Question

calculati suma tuturor nr ab stiind ca ab=3(2a+b)

Answer 1

ab=3*(2a+b)
10a+b=6a+3b
10a-6a=3b-b
4a=2b

1. a=1,b=2⇒ab=12
2.  a=2,b=4⇒ab=24
3. a=3,b=6⇒ab=36
4. a=4,b=8⇒ab=48

S=12+24+36+48
S=12(1+2+3+4)
S=12*10
S=120