Question

Wendall and Sarah are taking road trips. Wendall travels for 15x miles per hour for x hours. Sarah travels for 6 more hours than Wendall at a speed that is 8 miles per hour less than Wendall. Which of the following functions will give the total number of miles that Sarah traveled on her road trip?

A. ) t(x)= 15x^2-114x-48
B.) t(x)= 7x^2-48
C.) t(x)= 7x^2+6x
D.) t(x)= 15x^2+82x-48

Answer 1

Hello,

Wendall travels for x hours, and Sarah travels for 6 more hours than Wendal, so
Sarah travels: (x+6) hours

Wendal's speed is:
`15 x\,\,(mi)/(h)`. Sarah travels 8 miles per hour less than Wendal, so:
Sarah's speed=
`(15 x-8)\,\,(mi)/(h)`


`d=v*t \\ d=(15x-8)(x+6) \\ d=15 x^(2)+90x-8x-48 \\ \boxed{d=15 x^(2) +82x-48}`

Answer: D