There are 100 chickens and rabbits, a total of 350 feet, and how many chickens and rabbits there are

Hello: This problem can be solved by arithmetic method and equation method:

Arithmetic ideas: Suppose that all are an animal, but the number of legs does not meet the requirements, and the difference between the number of each leg of chickens and rabbits is 2, divide the difference between the actual number of legs and the hypothetical number of legs by 2.

Column: The number of rabbits: (100*4-350) (4-2)50 2=25 (only).

There are 100-25 = 75 chickens

Answer: There are 75 chickens and 25 rabbits.

Equation idea: Suppose one is x, then the other has (100-x). Adding up their legs equals 350 legs, using this equation.

Column equation: Solution: There are chickens x and rabbits (100-x).

2x+4（100-x）=350

2x+400-4x=350

Move item get: 2x=50

x=25100-x=100-25=75

So there are 25 chickens and 75 rabbits.

Of course, you can also assume that all of them are chickens, or that there are x rabbits, and try the rest yourself.

Good luck with your math progress!

If all chickens are chickens, then chicken feet are 100*2=200.

350-200 = 150 feet, 150 2 = 75 rabbits, 100-75 = 25 chickens.

Each animal lifts 2 feet up for Lao Tzu, stopper? The chickens are all gone.

It's only 150 feet of a rabbit.

Now each rabbit has only 2 legs. The one who spoke.

There are 75 rabbits.

25 --- chickens.

First look at it all as chickens, rabbits have:

Spike 280-100 2) (4-2).

Refers to 40 only ethnic states.

Chickens: 100-40 = 60.

Assuming it's all chickens, then rabbits have:

284-100 2) (4-2), =84 2, =42 (only), then the chicken has: 100-42=58 (only);

A: There are 58 chickens and 42 rabbits

Chicken = 90 2 = 45

There are 45 chickens, and the question is wrong.

Untie. Set: Chickens have x, rabbits have and keys disturb y.

then x+y=30

2x+4y=80

It is bent out of x=20 y=10

The number of chicken feet is 60 more than the number of rabbit feet.

Indicates that chickens are more than twice as large as rabbits.

60 Crack Lack of Argument Slip 2 = 30.

Therefore: rabbit: (120-30) 2+1) = 30 chicken: 120-30 = 90

Good luck with your studies!

Analysis: Suppose there are x chickens and y rabbits. From the known conditions, it can be known that there are 60 chickens and rabbits, so there are x+y=60

According to common sense, rabbits have 4 legs and chickens have 2 legs. So x chickens have a total of 2x legs, and y rabbits have a total of 4y legs. So 4y-2x=90

There are x chickens and y rabbits.

x+y=60

4y-2x=90

So x=25 y=35

A: There are 25 chickens and 35 rabbits.

Suppose they are a well-trained flock of chickens and rabbits, first order each to lift one foot, 100-36=64

Then command them to lift the other foot 64-36=28, it is known that the chicken has 2 feet, the chicken has fallen, and now the remaining 28 feet are all rabbits, and the rabbit has 4 legs, and after lifting 2, there are 2 left, then 28 divided by 2 = 14 rabbits, 36-14 = 22 chickens.

22 chickens and 14 rabbits. In the binary equation, let the chickens be x and the rabbits be y, x+y=36, and 2x+4y=100,

Rabbit four-legged: if 100 are all chickens 280-100*2=80

The extra 80 legs are the other two legs of the rabbit 80 2=40

So there are 40 rabbits 100-40=60 chickens.

Solution: If there are x chickens, then rabbits have (100-x), according to the title:

2x+4(100-x)=280

2x+400-4x=280

2x=-120

x=60, so 100-x=40

A: 60 chickens and 40 rabbits.

Set: chicken x, rabbit y.

x+y=100

2x+4y=280 (2 legs for a chicken, 4 legs for a rabbit) yields: x=60, y=40

Use the hypothetical method to solve.

Number of chickens: 4 100-280) (4-2) = 60 Rabbits: 100-60 = 40.

If there is a chicken x then a rabbit 100-x only.

2x+4(100-x)=280

2x+400-4x=280

4x-2x=400-280

2x=120

x=60A: 60 chickens and 40 rabbits.

Method 1:

It is well known that chickens have two legs and rabbits have four legs.

If the whistle is blown once, each animal raises one foot, blows twice, and each animal raises two feet (at this point, the chicken has no feet to lift, and each rabbit has two legs), 280-100x2=80 There are 80 feet left, 80 divided by 2=40,. So there are 40 rabbits and 60 chickens.

Method 2: Set x chickens and y rabbits.

Equation 1: x = 100-y

Equation 2: 2x+4y=280

Bring the equation into Equation 2 and solve x and y