Answer: H
Step-by-step explanation:
7% of 21 is 1.47
Answer:
5 weeks
Step-by-step explanation:
Let's find how much money she saves a week by multiplying the decimal form of 60% and $70.
To get the decimal form of a percent you have to move the decimal to the left twice, like this: 60 ---> .60
Now that we have the decimal form of the percent we can multiply it by the 70 to find how much she saves a week:
(70)(.6) = 42
Therefore, Kendra saves $42 each week.
To find how many weeks it will take Kendra to buy the game system you divide $210 by the $42. Like this:
(210)/(42) = 5
All in all, it will take Kendra 5 weeks to save enough money to buy a game system that costs $210.
<em>I hope this helps!!</em>
<em>- Kay :)</em>
<em />
I will explain you and pair two of the equations as an example to you. Then, you must pair the others.
1) Two circles are concentric if they have the same center and different radii.
2) The equation of a circle with center xc, yc, and radius r is:
(x - xc)^2 + (y - yc)^2 = r^2.
So, if you have that equation you can inmediately tell the coordinates of the center and the radius of the circle.
3) You can transform the equations given in your picture to the form (x -xc)^2 + (y -yc)^2 = r2 by completing squares.
Example:
Equation: 3x^2 + 3y^2 + 12x - 6y - 21 = 0
rearrange: 3x^2 + 12x + 3y^2 - 6y = 21
extract common factor 3: 3 (x^2 + 4x) + 3(y^2 -2y) = 3*7
=> (x^2 + 4x) + (y^2 - 2y) = 7
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 7
=> (x + 2)^2 + (y - 1)^2 = 12 => center = (-2,1), r = √12.
equation: 4x^2 + 4y^2 + 16x - 8y - 308 = 0
rearrange: 4x^2 + 16x + 4y^2 - 8y = 308
common factor 4: 4 (x^2 + 4x) + 4(y^2 -8y) = 4*77
=> (x^2 + 4x) + (y^2 - 2y) = 77
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 77
=> (x + 2)^2 + (y - 1)^2 = 82 => center = (-2,1), r = √82
Therefore, you conclude that these two circumferences have the same center and differet r, so they are concentric.
Answer:
v = 96 km/h
Step-by-step explanation:
Data:
d = 240 km
t = 2.5 h
speed = d/t
speed = 240/2.5 = 96 km/h
