since the graph has direct variation as data in x axis increases y also increases.
so we need to find how many miles travelled per galloon .
we distance travelled per gallon =total distance travelled/galoons of fuel used.
[tex] Distance travelled per gallon=200 miles/400 gallons=0.5 litres travelled per gallon [/tex]
for part b) slope=rise/run
[tex] m=(y2-y1)/(x2-x1) [/tex]
[tex] y2=400
y1=0
x1=0
x2=200 [/tex]
[tex] m=(400-0)/(200-0)=2 [/tex]
slope of the graph is 2
