Question

Determinați valoarea expresiei===> E=3a+8b+6c, ştiind că a+2b=5,2 ; b+3c=4,2 Va rooog urgent.

Answer 1

a+2b=5.2⇒ a=5.2-2b
b+3c=4.2⇒ b=4.2-3c
a=5.2-8.4+6c
E=-9.6+18c+33.6-24c+6c=24

Answer 2

a+2b=5,2 |*3
b+3c=4,2 | *2

3a+6b=15,6
2b+6c=8,4

Adunam cele doua expresii

3a+6b+2b+6c=15,6+8,4

3a+8b+6c=24
Deci E=24