It would be the second one!!!
Answer:
9 and also -4
Step-by-step explanation:
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
Answer:
the equation D ) would cause a consistent-independent system.
Step-by-step explanation:
A ) 5 x + y = 7 /*( -2 )
10 x + 2 y = 14
--------------------
- 10 x - 2 y = - 14
10 x + 2 y = 14
------------------------
0 x = 0 ( Dependent system )
B ) 5 x + y = 7 / * 3
- 15 x - 3 y = - 6
--------------------------
15 x + 3 y = 21
- 15 x - 3 y = - 6
-------------------------
0 x = 15 ( Inconsistent system )
C ) 5 x + y = 7
5 x + y = - 7 / * ( - 1 )
---------------------------
5 x + y = 7
- 5 x - y = 7
------------------
0 x = 14 ( Inconsistent system )
D ) 5 x + y = 7 / * ( - 2 )
6 x + 2 y = 7
------------------
- 10 x - 2 y = - 14
6 x + 2 y = 7
-----------------------
- 4 x = - 7; x = 7/4; y = - 7/4
