4z>-6
divide by 4
z>-6/4
z>-3/2
x+19<= -5
subtract 19 from both side
x<= -24
Answer:
A and C
Step-by-step explanation:
Sum divided by count. Add up all the numbers and divide it by how many numbers it is.
Answer:
2/12
Step-by-step explanation:
4w=2/3
1/4(4w)=1/4 x 2/3
w=2/12
Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
