Answer: x² + y² = 25
Step-by-step explanation: As we have x²+y²=25 (A) as options,
x-y=1 (B)
x+y=25 (C)
x²+y²=5 (D)
We can rule out B and C as they are not circles. Circles must be
(x - xc)² + (y - yc)² = r². They must have index 2.
We have then A or D.
As the circle must pass through (3,4), we can substitute as x=3 and y=4
(A) 3² + 4² = 9 + 16 = 25 ok
(D) 3² + 4² = 9 + 16 = 25 ≠ 5
So, it is A, x² + y² = 25
Distance =2/5 mile
Time = 2/7 hour
Rte = Distance/time = (2/5) / (2/7) = (2/5) X (7/2) = 7/5 miles/hour
