Step-by-step explanation:
area of a circle
A = pi x r^2
r=9
Step-by-step explanation:
2×length + 2×width = 45
length = 4×width
now, we are using the second equation (a variable identity) in the first equation
2×4×width + 2×width = 45
8×width + 2×width = 45
10×width = 45
width = 45/10 = 4.5 in
length = 4×width = 4×4.5 = 18 in
the area of the rectangle is
length × width = 18 × 4.5 = 81 in²
Answer:the third option is correct
Step-by-step explanation:
The system of equations are
y = 2x^2 - 5x - 7 - - - - - - - - - - -1
y = 2x + 2 - - - - - - - - - - - - - 2
We would equate equation 1 and equation 2. It becomes
2x^2 - 5x - 7 = 2x + 2
2x^2 - 5x - 2x - 7 - 2 = 0
2x^2 - 7x - 9 = 0
We would find two numbers such that their sum or difference is -7x and their product is - 18x^2. The two numbers are 2x and - 9x. Therefore
2x^2 + 2x - 9x - 9 = 0
2x(x + 1) - 9(x + 1) = 0
2x - 9 = 0 or x + 1 = 0
2x = 9 or x = - 1
x = 9/2 = 4.5
Substituting x = 4.5 or x = -1 into equation 2, it becomes
y = 2 × 4.5 + 2 or y = 2 × - 1 + 2
y = 11 or y = 0
Therefore, the solutions are
(4.5, 11) (- 1, 0)
The answer is 4 as 4x4 is 16 (squared means the number multiplied by itself) and
<em>16+16+9=41</em>
Therefore the answer is x=4
Answer:
Yes
Step-by-step explanation:
Remember in order for the rates to be proportional it has to have a constant rate of change and it has to go through the origin if graphed
For one this has a constant rate of change which is 3 dollars per 25 messages
Now we just have to find out if it would go through the origin (0,0)
To do so we subtract 3 dollars and then 25 messages
6-3=3
50 - 25 =25
then again 25-25=0
3-3=0
concluding that (0,0) is a solution
Thus meaning that this is a proportional relationship
