Răspuns :
14x+36y=18960⇒
dar y=4x
14x+144x=18960
158x=18960
x=18960:4
x=120
y=4x=4×120
y=480
Verificare
14x+36y=18960
14×120+36×480=18960
18960=18960
x⇒cat costa un metru de stofa din primul balot
y⇒cat costa un metru de stofa din al doilea balot
14x+36y=18960
14x+36*4x=18960
14x+144x=18960
158x=18960
x=18960:158
x=120
y=120*4=480
y⇒cat costa un metru de stofa din al doilea balot
14x+36y=18960
14x+36*4x=18960
14x+144x=18960
158x=18960
x=18960:158
x=120
y=120*4=480