Question

determinati nr a,b c stiind ca:a)a+b=100;b+c=110;a+c=90;b)a+b=84;b+c=64;a+c=34

Answer 1

a)a=100-b
c=110-b
a+c=90⇒100-b+110-b=90
-2b+210=90
-2b=-210+90
-2b=-120    (-1)
b=120/2
b=60
a=100-b=100-60=40
Δc=110-b=110-60=50
b)
a=84-b
c=64-b
a+c=34⇒84-b+64-b=34
-2b+148=34
-2b=-148+34
-2b=-114   (-1)
b=114/2
b=57
a=84-b=84-57=27
c=64-b=64-57=7