Question

Afla a,b,c, stiind că:


a+2b+4c=98,
b+c=22,
a+c=42.​

Answer 1

a+2b+4c=98

b+c=22

a+c=42

___________

a+c=42

=> c=42-a

b+c=22

=> b=22-c

=> b=22-42-a

=> b= -20-a

a+2b+4c=98

=> a+2(-20-a)+4(42-a)=98

=> a-40-2a+168-4a=98

=> a-2a-4a=98-168+40

=> -5a= -30

=> a= -30/-5

=> a= 6

a+c=42

=> 6+c=42

=> c=42-6

=> c=36

b+c=22

=> b+36=22

=> b=22-36

=> b= -14

Răspuns:

a=6

b= -14

c=36