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Svet_ta [14]
3 years ago
15

Andreas wants to estimate how many fish there are in a lake. One day he catches 20 fish,marks them,and returns them to the lake.

The next day he catches 10 fish of which four are marked. Estimate the number of fish in the lake.
Mathematics
1 answer:
tensa zangetsu [6.8K]3 years ago
8 0

Answer:

50

Step-by-step explanation:

The ratio of marked fish to caught fish is 4:10, we need to solve for x in 20:x, since 4 * 5 = 20, 10 * 5 = x so x = 50 fish.

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McKenna and Lara work for their uncle Eddie who repairs skateboards and bicycles. Uncle Eddie is leaving for a vacation to the A
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Let x be a number of skateboards and y be the number of bicycles in Eddie's repair shop.

Eddie asks the girls to order 54 new wheels for 21 skateboards and bicycles, then

x+y=21.

One scateboard has 4 wheels, then x scateboards have 4x wheels, one bicycle has 2 wheels, then y bicycles have 2y wheels. In total there should be ordered 54 wheels, so

4x+2y=54.

Solve the system of equations:

\left\{\begin{array}{l}x+y=21\\4x+2y=54.\end{array}\right.

From the first equation x=21-y. Substitute it into the second equation:

4(21-y)+2y=54,\\ \\84-4y+2y=54,\\ \\-2y=54-84,\\ \\-2y=-30,\\ \\2y=30,\\ \\y=15.

Then

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8 0
3 years ago
I really need help with this problem steps
melamori03 [73]
Solve for y by setting one equation =to X after that you can substitute the equation into the other one let's set the first one in X= FORM
X-7y=10
-2x+14y=-20

Add 7y to both sides of the first equation to let x stand alone
X=7y+10
Now you can substitute x on the second equation
-2 (7y+10)+14y=-20
Distribute
-14y-20+14y=-20
Add and simplify
Us cancel out =0
-20=-20
0=0
They are the same equations you can also divide the second equation by -2 which would make it look like this
X-7y=10
-2 (x-7y=10)
Let me know if I have answered your question
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Answer:

No they are not equal

Step-by-step explanation:

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