The equation of the circle:

where:
(a; b) - coordinates of the center
r - a radius
Use:

We have:
Answer:The center: (-2; 4)The radius: r = 4
Answer:
7/2
Step-by-step explanation:
he will have eaten 3.5 grapefruits in 7 days
7/2= 3.5
For this case we can make the following rule of three:
21 ------> 70%
x --------> 100%
Clearing x we have:
x = (100/70) * (21)
Rewriting we have:
x = (10/7) * (21)
x = 30
Thus,
21 is 70% of 30
Answer:
21 is 70% of 30
C = 0.3*-2.7 = -0.81
Hope it helps:)
the answer to your question is A.