Cos38 = 7,8/x
X= 7,8/cos38
= 9,90
Given:
Number of passengers seated in the roller coaster = 21
Empty seats = 3
Number of cars in roller coaster = 4 (each with the same number of seats)
To find:
An equation that can be used to determine the number of seats in each car.
Solution:
Let s be the number of seats in each car.
Total number of seats in 4 cars = 4s
Using the given information,
Total number of seats = Occupied seated + Empty seats
= 21 + 3
= 24
Now, the required equation is
Therefore, the required equation is .
Divide both sides by 4.
Therefore, the number of seats in each car is 6.
Here you have to find which each variable is, for this you start of picking one equation,
x + 2y + 6z = 4
-3x + 2y - 2 = -4
4x + 2z = 16
depending the equation you pick you multiply that by a certain number that will give you the opposite of one of the other equations,
-1(x + 2y + 6z = 4)
= -x -2y - 6z = -4
With this you add or subtract it with the equation that has the same number or variable, or both,
In this case it will be the equation,
-3x + 2y + 6z = 4
You can use this one or the third equation since both have a positive 2y which will cancel with -2y from the new equation,
-x - 2y - 6z = -4
-3x + 2y -z = -4
= -4x -7z = -8
Now you since you just eliminated the variable (y) you now have 2 variables, and the last equation has only 2 variables, meaning now you find the answer to those to equations,
-4x -7z = -8
4x + 2z = 16
= -5z = 8
Now leave the variable by itself,
z = 8/5
Now you found the variable (z), with this just substitute on one of the equations we used to find (z) so you can find (x), after that substitute those answered to on of the original equations so you can find (y)
Answer:
a. 61.92 in²
b. 21.396 ≈ 21.4%
c. $4.71
Step-by-step explanation:
a. Amount of waste = area of rectangular piece of stock - area of two identical circles cut out
Area of rectangular piece of stock = 24 in × 12 in = 288 in²
Area of the two circles = 2(πr²)
Use 3.14 as π
radius = ½*12 = 6
Area of two circles = 2(3.14*6²) = 226.08 in²
Amount of waste = 288 - 226.08 = 61.92 in²
b. % of the original stock wasted = amount of waste ÷ original stock × 100
= 61.92/288 × 100 = 6,162/288 = 21.396 ≈ 21.4%
c. 288 in² of the piece of stock costs $12.00,
Each cut-out circle of 113.04 in² (226.08/2) will cost = (12*113.04)/288
= 1,356.48/288 = $4.71.
