In the first year of junior high school, I want a correct answer, thank you! x b c a x c a b x

x=a+b+c

x-b-c )/a +(x-c-a )/b + x-a-b )/c[(x-b-c-a)+a]/a+[(x-c-a-b)+b]/b[(x-a-b-c )+c]/c

x-a-b-c)*(1 a+1 b+1 c)+3 gets: original = (x-a-b-c)*(1 a+1 b+1 c) = 0 because (1 a+1 b+1 c) is not equal to 0

So x-a-b-c=0

Get x=a+b+c

By the question. x-b-c)/a+(x-a-c)/b+(x-a-b)/c-1-1-1=0

x-b-c)/a-a/a+(x-a-c)/b-b/b+(x-a-b)/c-c/c=o

(x-a-b-c) a+(x-a-b-c) b+(x-a-b-c) c=0 with the same denominator

Merge (x-a-b-c) (1 a+1 b+1 c) = 0 and 1 a+1 b+1 c is not equal to zero.

So x-a-b-c=0

i.e. x=a+b+c

Observe and know. a b c is symmetrical in the equation.

Interchangeable. Then it is possible to replace the three of them with an identical unknown.

It's convenient that way.

1. Hundred digits = 2x-1

Single digit = 3x

3x+x+2x-1=11

The three-digit number of 6x=12x=2 is 326

2、|a+1|>=0

b-1) = 0

So a+1=0

b-1=0a=-1

b = 1 to the power of 2010 + 2009 to the power of b = 1 + 1 = 2

3262,|a+1|+(b-1) to the fourth power = 0, then |a+1|+(b-1)=0, you can know |a+1|=0, we can know that (b-1)=0i.e. a=-1, b=1

1. The ten-digit number is x, according to the known conditions, the single-digit number is 3x, and the hundred-digit number is 2x-1

2x-1）+x+3x=11

x = 2 single digits are 6 and 100 digits are 3, so this three-digit number is 326.

Solution: There are x students in this photo. x≥∴

A: There are at least 4 students in this photo

I've done it a long time ago

Solution: Known|a-2|+|b+3|+|c+1|=0 Each item is 0

So, a=2 b=-3 c=-1

So a-(-b)-c

0 attention to adopt.

a is equal to 2, b is equal to -3, c is equal to -1 and the original formula is equal to 0

13..If there are 4 people in each dormitory, there are 20 people left, and if there are 8 people in each room, there is a room that is not empty and dissatisfied.

Solution: There are x rooms.

4x＋20=8x-8

4x-8x=-8-20

4x=-28

x=74 7+20=48 (person).

A: There are 7 rooms and 48 people.

14. .A transportation company has two kinds of trucks, 2 large and 3 small cars can transport tons of goods, 5 large cars and 6 small cars can transport 35 tons of goods, customer Wang has 52 tons of goods, requiring a one-time use of the same number of large and small trucks to transport out, how many large and small trucks are needed?

Solution: Set up a large car can transport x tons of goods, and a small car can transport y tons of goods.

Curly braces 2x+3y=

5x+6y=35 ②

2. Gotcha. 4x+6y=31③

Get. x=4 substitute x=4 into .

2×4+3y=

The solution of y=so the solution of this equation is.

Curly braces x=4

y=Solution: Set up z carts and z trolleys.

4z z=8 A: With 8 large carts, 8 small carts.

1 In the equation , if is a solution to , then the value of is

This question is untitled. 2 The difference between the large number and the decimal number is , and the sum of the two numbers is , then the large number is and the decimal is

Ditto 3 Buy a pencil and this exercise book, share the yuan If the pencil is each yuan, the exercise book is each yuan, and write the equation with and is unknown

Untitled. 4 The ratio of the speed of A and B is , then the ratio of the distance they have traveled in the same time is the ratio of the time it takes them to cover the same distance

5 If the number of white sheep in the fold is less than the number of feet of the black sheep, and the number of the black sheep is less than the number of feet of the white sheep, then there shall be one white sheep and one black sheep

Untitled. 2. The circumference of a rectangle is 44cm, if 3 times the width is 6cm more than the length, what is the length and width of the rectangle?

Solution: Set the length to xcm and the width to ycm

Curly braces 3y-x=6

2x+2y=44 ②

2. Gotcha. 6y-2x=12③

Get. 8y=56

y=7 substitute y=7 into .

3×7-x=6

x=-15x=15

A: The length is 15cm and the width is 7cm.

3. It is known that the height of the trapezoid is 7, the area is 56cm2, and its upper bottom is 4cm more than one-third of the lower bottom, what is the length of the upper and lower bottom of the trapezoid?

Set the upper bottom x the lower bottom y

by the title. 7（x+y）/2=56

x-4=1/3 y

The solution is x=7y=9