Answer:the repair shop is 5km from her house.
Step-by-step explanation:
Let x represent the distance of the repair shop from her house.
Let y represent Emily's speed when riding.
Distance = speed × time
It took Emily 25 min to ride her bike to the repair shop. Converting 25 min to hours, it becomes 25/60 = 5/12 hours.
Distance covered,
x = y × 5/12 = 5y/12
It took her 1h 15 min to walk back home. Converting to hours, it becomes 1 + 15/60 = 1 1/4 = 5/4
If she can ride her bike 8km/h faster than she can walk, it means that her speed while walking would be y 8 8
Therefore,
Distance covered,
x= 5/4(y - 8) = (5y - 40)/4
Since the distance remains the same, then
5y/12 =(5y - 40)/4
Crossmultiplying, it becomes
5y × 4 = 12(5y - 40)
20y = 60y - 480
60y - 20y = 480
40y = 480
y = 480/40 = 12
x = 5y/12 = 5 × 12/12 = 5 km
Answer:
Step-by-step explanation:
6(-2.1k-2)+(7k+5)
-12.6k-12+7k+5
-5.6k-7
We know that:

is an equation of a circle.
When we substitute x and y (from the pairs we have), we'll get a system of equations:

and all we have to do is solve it for a, b and r.
There will be:

From equations (II) and (III) we have:

and from (I) and (II):

Now we can easly calculate a and b:

Finally we calculate

:

And the equation of the circle is:
Answer:
The answer is D. Multiply the previous value by 3.
Step-by-step explanation: