SOLUTION: A biker sees a derr crossing the street and puts on the breaks. The distance that he travels in feet can be modeled by D(s)=30+5squaroot(s) where s is the speed iof the bikes in mi

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A biker sees a derr crossing the street and puts on the breaks. The distance that he travels in feet can be modeled by D(s)=30+5squaroot(s) where s is the speed iof the bikes in mi      Log On


   

Question 1011874: A biker sees a derr crossing the street and puts on the breaks. The distance that he travels in feet can be modeled by D(s)=30+5squaroot(s) where s is the speed iof the bikes in miles per hr. if the bike travels a distance of 58 ft what was his speed?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the equation is d(s) = 30 + 5*sqrt(s).

you are given that d(s) = 58.

the equation becomes 58 = 30 + 5 * sqrt(s).

subtract 30 from both sides of the equation to get 28 = 5 * sqrt(s).

divide both sides of the equation by 5 rto get 28/5 = sqrt(s).

square both sides of the equation to get (28/5)^2 = s.

solve for s to get s = 31.36.

replace s in the original equation to get:

58 = 30 + 5 * sqrt(31.36)

evalute the equation to get 58 = 58.

this confirms the solution is correct.