The answer you have selected is correct. The answer to this question is 90.
(1/4)*(8/1)
(1*8)/(4*1)8/42 miles
Answer:
Width = 86 feet
Step-by-step explanation:
Create two equations with the info:
L = 27 + W
where L represents the length and W the width of the backyard.
The other one is about the area of the rectangular backyard:
Area = L x W
where you replace the area with 9718 and the length (L) with (27 + W):
and solve for W using the quadratic equation:
This gives us two solutions:
W = - 113
and W = 86
We use the positive solution since this is a distance.
Therefore the width is: 86 feet
Let`s assume that points M, N and P are the touching points of those 3 circles:Then:Y M + M Z = 14,Z N + N X = 20X P + P Y = 18And also: M Z = ZN, Y M = P Y and N X = X P.Now we have a system of 3 equations ( Y M, M Z and X P are the radii of each circle ):Y M + M Z = 14M Z + X P = 20X P + Y M = 18 Y M - M Z = - 14+X P + Y M = 18 X P - M Z = 4Y M - M Z = - 14+M Z + X P = 20 X P - Y M = 6 /* ( - 1 )X P - M Z = 4 X P + Y M = - 6 X P - M Z = 4 Y M - M Z = - 2 Y M + M Z = 14 2 Y M = 12 => Y M = 6M Z - 6 = 2 => M Z = 8X P + 6 = 18
X P = 12
Radii of the circles are: 12, 8 and 6.
Let's first establish what we already know for this problem.
x = total number of hotdogs sold
y = total profit from total sales of hotdogs
Let's also establish the other equations which we will require in order to solve this problem.
Equation No. 1 -
Profit for 40 hotdogs = $90 profit
Equation No. 2 -
Profit for 80 hotdogs = $210 profit
STEP-BY-STEP SOLUTION
From this, we can use the formula y = mx + b & substitute the values for x & y from one of the two previous equations into the formula in order to obtain the values of m & b for the final equation. Here is an example of the working out as displayed below:
Firstly, using the first or second equation, we make either m or b the subject. Here I have used the first equation and made m the subject:
Equation No. 1 -
y = mx + b
90 = m ( 40 ) + b
40m = 90 - b
m = ( 90 - b ) / 40
Now, make b the subject in the second equation as displayed below:
Equation No. 2 -
y = mx + b
210 = m ( 80 ) + b
210 = 80m + b
b = 210 - 80m
Then, substitute m from the first equation into the second equation.
Equation No. 2 -
b = 210 - 80m
b = 210 - 80 [ ( 90 - b ) / 40 ]
b = 210 - [ 80 ( 90 - b ) / 40 ]
b = 210 - 2 ( 90 - b )
b = 210 - 180 - 2b
b - 2b = 30
- b = 30
b = - 30
Now, substitute b from the second equation into the first equation.
Equation No. 1 -
m = ( 90 - b ) / 40
m = ( 90 - ( - 30 ) / 40
m = ( 90 + 30 ) / 40
m = 120 / 40
m = 3
Through this, we have established that:
m = 3
b = - 30
Therefore, the final equation to model the final profit, y, based on the number of hotdogs sold, x, is as follows:
y = mx + b
y = ( 3 )x + ( - 30 )
ANSWER:
y = 3x - 30