Easy,
write the coordinates out in pairs:
x= hours
y= earnings
(1,10)
(2,20)
(3,30)
(4,40)
(5,50)
Now it makes it much easier to see the increase,
After 1 hour of working she has made $10
After 2 hours of working she has made $20
After 3 hours of working she has made $30
And so on,
that being said it's easily seen that she is getting paid $10
Thus the unit rate is $10.
