Question

E=3xA+8xB+6xC, stiind ca a+2xb=5,2 si b+3xc=4,2

Answer 1

3a+8b +6c= 3(a+2b) + 2(b+3c)=  3* 5,2 +2*4,2= 15,6 + 8,4= 24

Answer 2

E = 3A+8B+6C

A+2B = 5,2 I ·3
3A+6B = 15,6

B+3C = 4,2 I ·2
2B+6C = 8,4

E = 3A+6B+2B+6C = 15,6 + 8,4 = 24