Answer:
A)
15 hours
B)
108 hours
C)
2074.29 miles
Step-by-step explanation:
Under the assumption the earth is a perfect circle, then in one complete rotation about its axis ( 24 hours) the Earth will cover 360 degrees or 2π radians.
A)
In every 24 hours the earth rotates through 360 degrees ( a complete rotation). We are required to determine the length of time it will take the Earth to rotate through 225 degrees. Let x be the duration it takes the earth to rotate through 225 degrees, then the following proportions hold;
(24/360) = (x/225)
solving for x;
x = (24/360) * 225 = 15 hours
B)
In 24 hours the earth rotates through an angle of 2π radians (a complete rotation) . We are required to determine the length of time it will take the Earth to rotate through 9π radians. Let x be the duration it takes the earth to rotate through 9π radians, then the following proportions hold;
(24/2π radians) = (x/9π radians)
Solving for x;
x = (24/2π radians)*9π radians = 108 hours
C)
If the diameter of the earth is 7920 miles, then in a day or 24 hours a point on the equator will rotate through a distance equal to the circumference of the Earth. Using the formula for the circumference of a circle;
circumference = 2*π*R = π*D
= 7920*3.142
= 24891.43 miles
Therefore a point on the equator covers a distance of 24891.43 miles in 24 hours. This will imply that the speed of the earth is approximately;
(24891.43miles)/(24 hours) = 1037.14 miles/hr
The distance covered by the point in 2 hours will thus be;
1037.14 * 2 = 2074.29 miles
Hi there!
In order to use the elimination method, you have to create one variable that has the same coefficient. This is to be able to eliminate one variable and have a one variable equation (which you can then solve).
In your case, we'll have the "x" have the same coefficient by multiplying the top equation by 4 and the bottom equation by 2 :
4( -2x + 3y = -4) → -8x + 12y = -16
2( 4x - 2y = 16) → 8x - 4y = 32
Now that both of your equation have a variable with the same coefficient, you need to choose rather you need to add or subtract the equations in order to get rid of the variable (in this case we want to get rid of the "x").
In your case, you want to add both equation together which will give you :
8y = 16
Now that you only have one variable, all you need to do now is solve the equation for "y" :
8y = 16
Divide each side of the equation by 8
y = 2 → Your answer
There you go! I really hope this helped, if there's anything just let me know! :)
All the x values are made negative
X = 4
F(x) = 2x
F(4) = 2(4)
F(4)= 8
X = 4 (still)
F(-x) = 2(-x)
F(-4) = 2 (-4)
F(-4) = -8
3 years ago:
m - 3 = 3(b - 3)
m - 3 = 3b - 9
m + 6 = 3b
m/3 + 2 = b
5 years from now:
m + 5 = 2(b + 5)
m + 5 = 2b + 10
m - 5 = 2b
m/2 - 5/2 = b
combine:
m/3 + 2 = m/2 - 5/2
1. multiply by 6
2m + 12 = 3m - 15
2. add 15 - 2m to both sides
27 = m
Marry is 27 years old.
60 miles for cheetah i don't know the other
