3x-20=y x+y=180

3x-20=y x+y=180

3x-20+x+y=y+180
4x=200
x=50
150-20=y
y=130
A: x = 50, y = 130

3X+2y+z=20 x+y+z=10 Y=3X

3X+2y+z=20(1) x+y+z=10(2) Y=3X（3）
(1) (2) get 2x + y = 10 (4)
Substituting (3) into (4) gives x = 2
Substituting x = 2 into (3) yields y = 6
So z = 2

Let x square + 3x = y, then the equation x to the fourth power + 6x to the third power + x square - 24x-20 = 0 can be transformed into the equation about y

x^4+3x³+3x³+9x²-8x²-24x-20=0x²(x²+3x)+3x(x²+3x)-8(x²+3x)-20=0(x²+3x)²-8(x²+3x)-20=0y²-8y-20=0

1.x-(3x-1)=5(x+2） 2.2（x+1）=1-（x+3) 3.20-y=6y-4（y-11）4.2-（4-y)=6y-2（y+1)

(1) X-3x + 1 = 5x + 10 x-3x-5x = 10-1-7x = 9x = - 9 / 7 (2) 2x + 2 = 1-x-32x + x = 1-3-23x = - 4x = - 4 / 3 (3) 20-y = 6y-4y + 44-y-6y + 4Y = 44-20-3y = 22y = - 22 / 3 (4) 2-4 + y = 6y-2y-6y + 2Y = - 2-2 + 4-3y = 0y = 0 is the third question wrong

There are 18 chickens and rabbits in the same cage, and they have the same number of legs. How many chickens and rabbits are there?

Because the chicken has two legs and the rabbit has four
So when the number of legs of chicken and rabbit is the same, the number of chicken is 4 △ 2 = 2 times that of rabbit
There are 18 rabbits (2 + 1) = 6
There are 6 × 2 = 12 chickens

In a cage, there are chickens and rabbits. Count their feet. There are 20 in total. How many chickens and rabbits are there in the cage?
It's too difficult for me to understand the equation better. It's simple. Please, if it's good, who can I give 15 integrals to

Because the chicken has two feet, the rabbit has four feet, but there is only one quantity in the question, so there are two answers: one, there are two chickens and four rabbits 2 * 2 + 4 * 4 = 20 2*8+1*4=20

Chickens and rabbits are in the same cage. There is one more chicken than rabbits. There are 38 feet in total. How many chickens and rabbits are there?

Method 1: suppose there are x rabbits and X + 1 chickens. According to the meaning of the question, 4x + 2 (x + 1) = 38 4x + 2x + 2 = 38 6x = 36 x = 6
There are six rabbits and seven chickens
Method 2: 38-2 = 36, a chicken and a rabbit have 2 + 4 = 6, 36 / 6 = 6, 6 + 1 = 7
A: there are seven chickens and six rabbits

Chicken and rabbit have 100 feet in total. If chicken is replaced by rabbit and rabbit is replaced by chicken, there will be 86 feet in total?

There are x chickens, X rabbits, and (100-2x) rabbits (100-2x) and (100-2x) 4, and the meaning of the title is: 4x + (100-2x) (100-2x) - 4 × 2 = 86, and & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; and the & nbsp; & nbsp; 4x + (100-2x) (100-2x) and the idea: 4x + (100-2x) (100-2x) (4-2x) (4-4 × 2 = 4 × 2 = 86, 4 × 2 = 86, & amp & nbsp; & nbsp; & nbsp; & & nbsp; & nbsp; & nbsp; & & nbsp; & nbsp; & & nbsp; & & nbsp; & & nbsp; & nbsp; & nbsp; & & nbsp; & & nbsp; & nbsp; & & nbsp; & nbsp; & nbsp; & & nbsp; & nbsp; & nbsp; & nbsp; & & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; &Nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 36 △ 3, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 12, then rabbits have: (100-2 × 12) △ 4 = 19. Answer: there are 12 chickens and 19 rabbits

Chickens and rabbits are in the same cage. There are 100 legs of chickens and rabbits. If chickens are replaced with rabbits and rabbits are replaced with chickens, there are 92 legs in total. How many chickens and rabbits are there?

There were x chickens and Y rabbits
2x + 4y = 100
4x + 2y = 92
x = 14 y =18
There are 14 chickens and 18 rabbits

Chicken and rabbit have 100 feet in total. If chicken is replaced by rabbit and rabbit is replaced by chicken, there will be 86 feet in total?

Suppose that there are x chickens and (100-2x) × 4 rabbits, the meaning of the question is as follows: 4x + (100-2x) × 4 × 2 = 86, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 4x + 50-x = 86, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp