That's not a function.
Since a vertical line hits the graph more than once, if fails the test. (See graph below)
If it is a function, any vertical line you draw can only hit the graph once.
A(b-c)=ab-ac
(1/7)(1/3h-1/2)=(1/7)(1/3h)-(1/7)(1/2)=1/21h-1/14
now we gots
6 and 1/7+1/21h-1/14
rearange
6 and 1/7-1/14+1/21h
make common denom which is 14
6 and 2/14-1/14+1/21h
6 and 1/14+1/21h
What is the question?????