1. Suzette ran and biked for a total of 60 mi in 6 h. Her average running speed was 4 mph and her average biking speed was 12 mph. Let x = total hours Suzette ran. Let y = total hours Suzette biked

Respuesta :

Suzette ran for 1.5 hours and biked for 4.5 hours

Step-by-step explanation:

The given is:

  • Suzette ran and biked for a total of 60 miles in 6 hours
  • Her average running speed was 4 mph
  • Her average biking speed was 12 mph
  • Let x = total hours Suzette ran
  • Let y = total hours Suzette biked

∵ x represents the total hours Suzette ran

∵ y represents the total hours Suzette biked

∵ Suzette ran and biked for a total 6 hours

x + y = 6 ⇒ (1)

∵ Her average running speed was 4 mph

∵ Her average biking speed was 12 mph

∵ Distance = speed × time

∴ Her total distance = 4 x + 12 y

∵ Suzette ran and biked for a total of 60 miles

- Equate the two expressions of her total distance

4 x + 12 y = 60 ⇒ (2)

Now let us solve the system of equations to find the values of x and y

Multiply equation (1) by -4 to eliminate x

∵ (-4) x + (-4) y = (-4)(6)

-4 x - 4 y = -24 ⇒ (3)

- Add equations (2) and (3)

∴ 8 y = 36

- Divide both sides by 8

y = 4.5

∴ Suzette biked for 4.5 hours

- Substitute the value of y in equation (1) to find the value of x

∵ x + 4.5 = 6

- Subtract 4.5 from both sides

x = 1.5

∴ Suzette ran for 1.5 hours

Suzette ran for 1.5 hours and biked for 4.5 hours

Learn more:

You can learn more about system of equations in brainly.com/question/6075514

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