Question

x+x+x=15
y+x+z=12
y+2z=10
2x+z-y=?

Answer 1

Răspuns:

X=15:3

X=3

Y+z=12-3=9

Y+z=9

Z=1

Y=9-1

Y=8

2x+z-y=6+1-8=7-8=-1

Answer 2

Răspuns:

x+x+x=15

3x=15=>x=15:3=>x=5

y+x+z=12

y+5+z=12=>y+z=12-5=>y+z=7

y+2z=10=>y=10-2z

10-2z+z=7

-z=7-10=>z=3

y+3=7=>y=7-3=>y=4

2x+z-y=2·5+3-4=10+3-4=9