The grade x of a hill is a measure of steepness and correlates to the slope of the freeway. the braking distance is D in ft for car traveling 60 miles per hr on a wet uphill grade is given by expression d(x) = 3600/ 30x+9 ...evaluate .12 = ? ft and find the grade for braking distance at 320 ft = ?

Question

The grade x of a hill is a measure of steepness and correlates to the slope of the freeway. the braking distance is D in ft for car traveling 60 miles per hr on a wet uphill grade is given by expression  d(x) = 3600/ 30x+9 ...evaluate .12 = ? ft and find the grade for braking distance at 320 ft = ?

anonymous · Answer

evaluate .12 = ? ft <---- what does this mean?

also substitute d(x) = 320 ft to find the grade in the second part.

anonymous · Answer

you have to  use.12ft and evaluate it to get ...answer ?

anonymous · Answer

does that mean x = 0.12?

anonymous · Answer

yes

anonymous · Answer

sorry it was hard to write it on here

anonymous · Answer

then substitute x = 0.12 in your expression and solve for d(x)