Super difficult equation calculation problems in the first year of junior high school, difficult equ

First, the Huaiyu solution equation. 32x+88=3480 204-x+76=196 x-(135-98)=25 4x-15=17 8 125-40x=600 Qiao Mingcheng 2x Minzheng 3 x+80 2=200 45-2x=10+15 8 4x=18 .

Categories: Education Science.

Problem description: To be a pure equation. Analysis:

Solve the following equations.

1) 6x 13 = 1 (2) 10x 1 = 14x 31) to get 6x = 1 13

Combine similar terms to get 6x=12

The coefficient is reduced to 1 to give x=2

2) Move the item to get 10x 14x = 3 1

Merge similar items to get 4x= 4

The coefficient is reduced to 1, resulting in x=1

If there are parentheses in the equation, try to solve them first.

Remove the brackets to get 8y 8 2y = 3y 8y 14 shift terms, get 8y 2y 3y 8y = 14 8

Combine similar terms to get y=22

The coefficient is reduced to 1 and we get y = 22

Remove the brackets to get 6x 12 20x 50=3x 9 90 move terms, and get 6x 20x 3x=9 90 12 50 merge similar terms to get 17x= 119

The coefficient is reduced to 1, resulting in x=7

By removing the brackets, shifting the terms and merging the same terms, the coefficient of 37t=259 is reduced to 1, and the coefficient is t=7

6.In the formula l=lo (1 at), it is known that l=,lo=80, =, and the idea of finding t is indicative: in this formula, although there are four letters l, lo, , t, the value of l, lo, is a known number, and there is only one unknown number t, so it is enough to solve the unary equation about t.

Substitute l=, lo=80, and = into the formula respectively.

t=1007.（x＋7）＋x＋3x=17

Solve x = solve this equation and get x = 86

10.(Tong Jingban x 3): x 3) = 80: 604 (x 3) = 3 (x 3).

x=2111.(20x 5) 3 (60x 4) = 5 (12 10x) without parentheses, 20x 5 180x 12=60 50x transfer merge, 20x 180x 50x=60 5 12 merge the same Hu category to get 110x=53

x=-53/110

Remove the parentheses to get x 6 = 6 x 1 x [4 x 2 x 3] x 6 = 7 x 1 2x 3

Merge similar terms to get x 6 = 5 x 2

Move the items and merge the same kind of items to get 8=4x

The coefficient is reduced to 1 to give 2=x

i.e. x = 2

Hello! It is recommended that you go to Xinhua Bookstore to buy a workbook for special exercises, and there are some questions compared to experimental classes, thank you!

I went to buy the exercise book of the Century Gold List, it was very good, it was very suitable for us, and I also used it with good results. "The Case of the Golden List".

The calculation questions in the seventh grade are very simple, the key is whether you practice often, whether you are serious in class, whether you understand, many questions you have to ask yourself first, understand.

General solution:

1.Denominator: multiply by the least common multiple of each denominator on both sides of the equation (the term without the denominator is also multiplied);

2.Remove braces: first go to the small braces, then the middle brackets, and finally the braces; (Remember to change the sign if there is a minus sign outside the parentheses).

3.Shift: Move all terms with unknowns to one side of the equation and all other terms to the other side of the equation; The move item needs to be renumbered.

4.Merge similar terms: Equations are formed in the form ax=b(a≠0);

5.The coefficient is 1: divide the coefficient a by the unknown number on both sides of the equation to get the solution of the equation x=b a

Solve the equation together. If the solution of two equations is the same, then the two equations are called same-solution equations.

Principle of Homogeneous Solution of Equations:

Adding or subtracting the same number or the same equation from both sides of the equation results in an equation that is the same solution as the original equation.

The equation obtained by multiplying or dividing by the same non-0 number on both sides of the equation is the same solution as the original equation.

Important ways to do unary equation application problems:

Carefully review the topic (review the topic).

Analyze known and unknown quantities.

Find a suitable equivalence relationship.

Assign an appropriate unknown.

Make a list of reasonable equations (columns).

Solve the equation (problem solving).

Test Write out the answer (answer).

ax=b solution: when a≠0 and b=0, ax=0

x=0 When a ≠ 0, x=b a.

When a=0, b=0, the equation has an infinite number of solutions (note: this case does not belong to the unary one-dimensional equation, but to the identity equation).

When a=0, b≠0, the equation has no solution.

Example: (3x+1) 2-2=(3x-2) 10-(2x+3) 5

Remove the denominator (multiply both sides of the equation by the least common multiple of each denominator) to get ,

5(3x+1)-10×2=(3x-2)-2(2x+3)

Go to the brackets,

15x+5-20=3x-2-4x-6

15x-3x+4x=-2-6-5+20

Merge similar items to obtain,

16x=7 coefficient is reduced to 1,

x=7/16。

Letter formulas. a=b a+c=b+c a-c=b-c

a=b ac=bc

a=bc(c≠0)= a÷c=b÷c

Find the root formula. Since the unary equation is a fundamental equation, the only solution in the textbook is the above method.

But for the unary linear equation in standard form ax+b=0

The formula for finding the root is x= -b a).

You need to understand the solution, the steps, and the process of the equation.

1)3(x3)=2x

2)2-3(1-x)=5

3)2(x-3)-6(2x-1)=-3(2-5x)4)5x-2(x-1)=14

2x=16)4x=3x

6)5x-15=10

7)4x-12=5x

8)4x-6

10=5x-5

9)2(x-1)

3x=1310)8x

5(1000-x)=6950

I'm almost dying, let's go 10 first, I'm tired, I'm going to, hehe!

1. Solve equations.

32x+88=3480 204-x+76=196 x-（135-98）=25 4x-15=17

8×125-40x=600 2x＋ 3＋

x+80×2=200 45-2x=10+15 8× 4x=18 6÷（ x）=

4＋x＋ x－ -6x = - x- = 7

5x =13 3x＋ 80x÷4＝12

2. List the equations and find the solutions to the equations.

1.60 is 3 times less than 30 times a number, what is this number?

2.4 times more than 60 24 more than a number, what is this number?

3. Divide the difference between a number and the quotient is 26, what is this number?

4. The multiple of a number is less than its 2 times, find this number?

35 more than 4 times a number, find this number.

The difference minus 157 is 5 times a number, what is this number?

3. Calculate the following questions. (If you can make a simple calculation, you should make a simple calculation).

Fourth, the application of the problem.

1. How much is the price of a volleyball?

2. The Young Pioneers helped the library repair books, and the first group repaired 42 more books than the second group. The first team consisted of 18 people, with an average of 6 copies per person. The second group of 12 people, how many copies of each person are repaired on average?

3. Two cars A and B are driving in opposite directions from City A at the same time. Car A travels kilometers per hour, and vehicle B travels kilometers per hour. How many hours after the two cars are 270 kilometers apart?

4. Haihong Primary School has 1,012 students, of which the number of boys is twice that of girls. How many more boys than girls?

5. The unit price of a fountain pen in the mall is 8 times that of a pencil. Xiao Wang bought 1 fountain pen and 3 pencils and paid a total of yuan. How much is 1 pen and 1 pencil each?

6. Mr. Wang plans to use 3 decimeter square bricks to pave the classroom, which requires 720 pieces. Later, how many square bricks with a side length of 4 decimeters were used?

7. The car travels 48 kilometers per hour, which is more than the multiple kilometers of the bicycle, how many kilometers does the bicycle travel per hour?

8. Two road repair teams A and B repair the road at the same time from both ends of the 4400-meter-long road, and complete the task in 8 days, the number of meters repaired by team A per day is twice that of B, how many meters does B repair every day?

9. The unit price of the fountain pen in the store is twice that of the pencil, and Li Yang paid more yuan for buying a fountain pen than buying a pencil. How much is a fountain pen worth?

10. 8 cars of cement were transported into the construction site in the morning, and 11 cars of cement were also transported in the afternoon, and the cement payment was 3180 yuan more in the afternoon than in the morning, and how much yuan was paid for cement in the morning?

11. Wang Hua bought 12 exercise books with 50 yuan, each yuan, and the rest of the money bought 4 fountain pens, how much yuan is each pen?

12. The investment in the second phase of Shuisi Lotus Garden is 3.86 million yuan, which is 640,000 yuan less than the first phase, how many yuan is invested in the first phase?

13. Students participated in the interest group, and there were 54 people in the painting group, which was 12 times less than twice that of the dance group, how many people participated in the dance group?

14. The area of a trapezoid is 180 square decimeters, its upper bottom is 15 decimeters, and the lower bottom is 21 decimeters, how many decimeters is its height?