Slope - Intercept form formula: y = mx + b
'm' represents the slope (unit rate)
'b' represents the y - intercept
Equation: y = 7x
Slope (unit rate): 7
Y-Intercept: 0
If you used 5 gallons of gasoline, you go 5 times the number of miles, which is 7, to get a total amount of 35 miles.
Unit rate = 7
The answer is B.