Question 841554
X+Y=320----eq1
X-80=Z-----eq2
X+60=Y----eq3

Substitute Y=X+60 from eq3 into eq1 and we get
X+X+60=320 collect like terms
2X=320-60=260
X=130---Substitute X=130 into eq3
130+60=Y
Y=190
Substitute X=130 into eq2
130-80=Z
Z=50

CK
X+Y=320
130+190=320
320=320
X-80=Z
130-80=50
50=50
X+60=Y
130+60=190
190=190

Hope this helps---ptaylor