If you want to buy an item in a store that cost $33 and is on sale for 25% off then how much would the item actually cost after
1 answer:
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First, make up some variables to represent the number of Girls and Boys in the choir.
B = number of boys
G = number of girls
You know that there are 4 times as many girls in the choir as boys. Therefore, the equation you can write is:
If you cross-multiply, then you get the simplified equation:
G = 4B
Intuitively this makes sense since if you multiplied the number of boys in the class by 4, that would be equal to the number of girls you have.
Now, we know that the total class size is 60. So girls plus boys equals 60:
G+B = 60
To solve the equation, replace the G in this equation with the replacement you found before, 4B.
G + B = 60 -->
4B + B = 60 -->
5B = 60 -->
B = 12
However, you are trying to find the number of girls, so plug the answer back into your equation.
G + B = 60 -->
G + 12 = 60 -->
G + 12 -12 = 60 - 12 -->
G = 48
The number of girls you have is 48.
B = number of boys
G = number of girls
You know that there are 4 times as many girls in the choir as boys. Therefore, the equation you can write is:
If you cross-multiply, then you get the simplified equation:
G = 4B
Intuitively this makes sense since if you multiplied the number of boys in the class by 4, that would be equal to the number of girls you have.
Now, we know that the total class size is 60. So girls plus boys equals 60:
G+B = 60
To solve the equation, replace the G in this equation with the replacement you found before, 4B.
G + B = 60 -->
4B + B = 60 -->
5B = 60 -->
B = 12
However, you are trying to find the number of girls, so plug the answer back into your equation.
G + B = 60 -->
G + 12 = 60 -->
G + 12 -12 = 60 - 12 -->
G = 48
The number of girls you have is 48.
I'll do problem 1 to get you started.
The answer to problem 1 is <u>3400 miles</u>
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Explanation for problem 1:
We're asked to find the perimeter, which is the total distance around the exterior or outside. In other words, we need to add up the four side lengths of this quadrilateral.
We'll need the distance formula to find the lengths of the slanted sides AB and BC
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Let's first find the length of segment AB
A = (x1,y1) = (0,0)
B = (x2,y2) = (400,300)
d = Length of AB
The distance from A to B is 500 miles. This is the same as saying segment AB is 500 miles long.
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Now find the length of segment BC
B = (x1,y1) = (400,300)
C = (x2,y2) = (-800,800)
d = length of BC
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The length of CD is fairly easy to find without needing the distance formula. This is because it is a vertical line. We subtract the y coordinates of C and D to get 800-0 = 800. So CD is 800 miles long.
Segment DA is a similar story. But we subtract the x coordinates. This only works for horizontal lines. DA is 800 miles long because |-800-0| = 800. Absolute value is used to make sure the distance is never negative.
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To summarize everything so far, we found these four side lengths
- AB = 500
- BC = 1300
- CD = 800
- DA = 800
The perimeter is going to be the sum of those four sides, leading to...
perimeter = sum of sides
perimeter = AB+BC+CD+DA
perimeter = 500+1300+800+800
perimeter = 3400 miles
This is the total distance traveled if you started at city A, went to B, then to C, then to D, and then finally went back to A.