Answer:
x= -5
x= 9
Step-by-step explanation:
It’s A because I did the test lmafo
Answer:
see explanation
Step-by-step explanation:
Given A is directly proportional to r² then the equation relating them is
A = kr² ← k is the constant of proportion
To find k use the condition when r = 5, A = 75 , then
75 = k × 5² = 25k ( divide both sides by 25 )
3 = k
A = 3r² ← equation of proportion
(a)
when r = 4, then
A = 3 × 4² = 3 × 16 = 48
(b)
when A = 147 , then
147 = 3r² ( divide both sides by 3 )
49 = r² ( take the square root of both sides )
r =
= 7
A. If you know the diameter, you can find the radius of a sphere by dividing the diameter in half. If you know the circumference, you can find the radius by dividing the circumference by 2 times pi
B. π × r2 × h