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26 votes
What is the cost of the hot dog?
What is the cost of one hamburger?pleaseeeee hellpppppp

What is the cost of the hot dog? What is the cost of one hamburger?pleaseeeee hellpppppp-example-1
User Chibueze Agwu
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3.2k points

2 Answers

12 votes
12 votes

Answer:

The prices must be $1.50 and $1.75

Explanation:

For instance, seven hot dogs and two hamburgers cost $14: 7D+2B=14

We also know that two hot dogs and seven hamburgers cost $15.25: 2D+7B=15.25

Now, if we combine these two equations, we have a system where EVERYTHING has to be true at the same time

7D+2B=14

2D+7B=15.25

From here there are a couple trick you should know to solve a system of equation, especially substitution and elimination. I see a coefficient of 2, so I'd rather use substitution by dividing the entire first equation in half:

3.5D+B=7

Now I'll solve for B

B=7-3.5D

Now that I've solved for a variable, I can substitute the solution into the other equation

2D+7( B )=15.25

becomes

2D+7(7-3.5D)=15.25

Now I can distribute and solve for D:

2D+49-24.5D=15.25

22.5D=33.75

D=1.5

Now we can replace D from either (or both) of our original equations and see what B has to be

7(1.5)+2B=14

10.5+2B=14

2B=3.5

B=1.75

2(1.5)+7B=15.25

3+7B=15.25

7B=12.25

B=1.75

The prices must be $1.50 and $1.75. The most important part of all this is setting up the equations, the rest is just being careful with your calculations.

User Fixedpoint
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2.5k points
13 votes
13 votes

Answer:

1 hot dog = $1.50 each

1 hamburger = $1.75 each

Explanation:

User Filipp
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2.8k points