Suzette ran and biked for a total of 50 mi in 4 h. her average running speed was 5 mph and her average biking speed was 15 mph.

let x = total hours suzette ran.

let y= total hours suzette biked.

use substitution to solve for x and y. show your work. check your solution.

(a) how many hours did suzette run?

(b) how many hours did suzette bike?

Step-by-step explanation:

Suzette ran and biked for a total of 50 miles in 4 hours. Her average running speed was 5 mph and her average biking speed was 15 mph.

Let x = total hours Suzette ran.

Let y= total hours Suzette biked.

Distance = speed × time

Distance covered in running for x hours at a speed of 5 miles per hour = 5×x = 5x miles

Distance covered in biking for y hours at a speed of 15 miles per hour = 15×y = 15y miles

Total distance covered is 50 miles. This means

5x + 15y = 50 - - - - - - - - 1

If the total time spent is 4 hours, that means

x + y = 4

Substituting x = 4 - y into equation 1,

It becomes

5(4 - y) + 15y = 50

20 - 5y + 15y = 50

- 5y + 15y = 50 - 20

10y = 30

y = 30/10 = 3

x = 4 - y = 4 - 3

x = 1

a) Suzette ran for 1 hour

b) Suzette biked for 3 hours

answer is:

1.75 pounds