Respuesta :
Answer:
From the information given
x is time for which she ran at speed of 6mi/h and
y is time for which she biked at speed of 12.5 mi/h
total time = 3.5 h
total distance = 34 mi
so
6x + 12.5y = 34 and
x + y = 3.5
x = 3.5 - y
6 ( 3.5 - y) + y = 34
6.5y = 13 which gives
y = 2 and this
x = 1.5
so suze ran for 1.5 h and biked for 2 h
CHECK
speed of run X time of run + speed of biking x time of biking must be = total distance covered
6 × 1.5 + 12.5 × 2 = 9 + 25= 34 mi
which is true
The speed of an object is the rate of distance traveled over time. Suzette ran for 1.5 hours, and she biked for 2 hours.
Given that:
[tex]Distance = 34mi[/tex]
[tex]Time = 3.5h[/tex]
Speed is calculated as:
[tex]Speed = \frac{Distance}{Time}[/tex]
Make Distance the subject
[tex]Distance = Speed \times Time[/tex]
Average running speed = 6 mph for x hours implies that:
[tex]Distance = 6 \times x[/tex]
[tex]Distance = 6x[/tex]
Average biking speed = 12.5 mph for y hours implies that:
[tex]Distance = 12.5 \times y[/tex]
[tex]Distance = 12.5y[/tex]
So, the total distance is:
[tex]Total = 6x + 12.5y[/tex]
The total distance is 34 miles. So, we have:
[tex]6x + 12.5y = 34[/tex]
The total time is 3.5h. So, we have:
[tex]x + y = 3.5[/tex]
Make x the subject
[tex]x = 3.5 - y[/tex]
Substitute [tex]x = 3.5 - y[/tex] in [tex]6x + 12.5y = 34[/tex]
[tex]6(3.5 - y) + 12.5y = 34[/tex]
[tex]21 - 6y + 12.5y = 34[/tex]
Collect like terms
[tex]- 6y + 12.5y = 34 - 21[/tex]
[tex]6.5y = 13[/tex]
Divide both sides by 6.5
[tex]y = 2[/tex]
Recall that:
[tex]x = 3.5 - y[/tex]
[tex]x = 3.5 - 2[/tex]
[tex]x = 1.5[/tex]
Hence, Suzette ran for 1.5 hours, and she biked for 2 hours.
Read more about speed at:
https://brainly.com/question/359790