A few questions on a one dimensional equation, the first 10 chasing high scores will do a few questi

1. Substituting y=1 can be: 2-3+4+m+7=0 to get m=-10

m^2-3m+2=100+30+2=1322、(|x|-2)^2+|3y+1|=0

Available|x|-2=0 3y+1=0

The solution gives x=+-2 y=-1 3

Both the square and the absolute value are non-negative, so they can only be 0).

3. (1) Let the odd number in the middle be x, then the other four numbers are x-2, x-1, x+1, x+2.

x-2+x+x+2)-(x-1+x+1)=15x=15, these five numbers are 13, 14, 15, 16, 17.

2) Set the amount of money your brother has saved to x.

4/3x-11=x+11+2

Solution x=72

4、(1)a≠0

x=b a2).

3) When a=0. 5、b

Knowing that -1 is the solution of the equation 2y 3-3y 2+4y+m+7=0 about y, find the value of the algebraic formula m 2-3m+2.

Answer: It is known that -1 is the solution of the equation 2y 3-3y 2+4y+m+7=0 about y.

This can be known.

y=-1 Substituting the above test yields: 3 times of -2y- -4+7 =0 of -2y

The answer can be answered: -2-3-4+7+m=0The answer is -2 Take a look, hehe.

Correct the answer to watertight watertight.

1, m 2, the answer to the algebraic formula is 0

4. (1) A is not equal to 0

2) Infinite number of solutions.

3）a＝1

You've been studying for years, and you can't even do this! China will be ruined in your hands!!

Oh, my God? You're still a primary school student...

I'm really convinced, you've been studying math for a few years.

Goose? It's also called a high score, stingy.

(1) Commodity ** teapot and teacup, each teapot is priced at 20 yuan, and each teacup is priced at 5 yuan

Buy a teapot and get a teacup; Pay at 90% of the total price A customer buys 5 teapots and several teacups (no less than 5), when the customer is asked how many teacups to buy, the two methods of payment are the same If the customer buys 20 teacups, which way to buy is more affordable.

2) A person originally planned to ride a bicycle at a speed of 12 kilometers per hour from A to B, so that he could arrive at the specified time, but he postponed the original scheduled departure time by 20 minutes, so he had to travel at a speed of 15 kilometers per hour, and arrived at B 4 minutes earlier than the specified time, finding the distance between A and B

3) A factory completes a batch of products, and it takes 30 days for the first workshop to be completed separately, and 20 days for the second workshop to be completed separately

For example, the first workshop will do it for a few days, and then continue to do it by the second workshop until it is completed, and it will be done for a total of 25 days before and after.

If the first workshop has been done for 3 days, and the second workshop has joined to do it together, how many days will it take to complete?

1. Solution: It is known that in the round-robin match, every 2 teams must play one game, so a team has to play one game each with the remaining 11 teams in this game, so the total number of games that a pair of scattered air has participated in is 11. Suppose the team wins x games, and the title knows that the team loses x-2 games, then the number of draws is:

11-x-(x-2)=13-2x

Field. The columnable equation is: 3x+(13-2x)*1+(x-2)*0=18 solution: x=5

A: The team has won 5 games.

2. Blind explanation: (1) The time for Xiao Wang to run 2 laps is the same as the time for his uncle to run 3 laps, and it is known that their distance ratio is 2:3, and the time is the same, then the ratio of their speed is 3:2 (s=v*t).

Let Xiao Wang's speed be 2x and Uncle's speed be 3x

The columnable equation is: (2x+3x)*32=400

Solution: x=then. Xiao Wang's speed is 5m s, and his uncle's speed is.

After setting TS, the first time the two met (that is, the uncle ran one lap more than Xiao Wang and surpassed him) The equation can be as follows:

Solution: t=160

That is, the two met for the first time after 160s.

I don't really understand what it means to face Xiangzhou, since the two are running in the same direction, how can they face each other? ）

1.If the name of the worker x who makes the shirt is 24 x5x=3(24-x) x=9 24-x=152Make a large x person, a small one is 34 x

16x/10(34-x)=2/3 x=10 34-x=24

Eight. 1 solves the hundred digits as x, then the single digit is 2x, the ten digits are (1+x), according to the title, 2 [100x+2x+10(1+x)]-49=200x+10(1+x)+x

13x=39

x=3 100x3+2x3+10(1+3)=346A:..I'll solve this problem with you because of the time, and I'll come back when I have time.

It's troublesome、、Think about it yourself、、Rely on yourself the most realistic。

19=25972 3000*x%*3=3243-3000

20 、 x+x*

8) 1. Let the number of hundreds be x, then (100x+10(x+1)+2)*2=200*2x+10*(x+1)+x+49 to get x=3, then the original number is 346

Top 1f, or find the equivalent relationship yourself.

19.Solution: The interest for three years is $x.

3x=3x=810

x=2430

25000 + 2430 = 27430 (yuan).

Ask the teacher! Don't keep looking it up online! It will harm itself.

(1) 10 with equal volume and high volume, original: (15 12 + 15 8 + 12 8) 2 = 792 cm square New: (12 12 + 12 * 10 + 12 * 10) * 2 = 768 cm square.

2) The purchase price is x,3120*(1-20%)=x*(1+17%)

3) Let the speed of A be 2a, and B is 3a, then (2+2)*2a+2*3a=140

4) It takes x minutes, and the speed of A is 80*5 4=100, 100x-80*(x-100 100)=400

5) If A works for x hours, then (1 10 + 1 15 + 1 20) * x + (1 15 + 1 20) * (6-x) = 1

6) Let these three consecutive even numbers be 2a-2, 2a, 2a+2, then (2a+2) 2+(2a-2)+2a=19

(1) (15 12 + 15 8 + 12 8) 2 = 792 cm square (12 12) 6 = 864 cm square.

What do you mean, you.,The question didn't add points.,Alas。。。

Elite Class 1Mom brought some money to buy cloth. After buying 2 meters of cloth, there is still yuan left; If you buy the same cloth 4 meters, the difference is yuan. Q: How much money did my mom bring?

2.The two pools store a total of 40 tons of water, 4 tons are injected into pool A, and 8 tons are released from pool B, the tonnage of water in pool A is equal to the tonnage of water in pool B, how many tons of water was stored in each of the two pools?

3.The four children of Xiaolong, Xiaohu, Xiaofang and Xiaoyuan have a total of 45 balls, but they don't know how many balls each person has, if you change it, Xiaolong's ball is reduced by 2, Xiaohu's ball is increased by 2, Xiaofang's ball is doubled, and Madoka's ball is reduced by half, then the number of four-person balls is the same. How many balls does each person have?

4.There are a group of tourists who need to be picked up by car. There are two kinds of cars, A and B, with 3 A cars, and 4 B cars (just fully loaded) need to run 5 times; If you use 5 A cars and 3 B cars (just fully loaded), you only need to run 4 times. What kind of car has more passengers?

5.There is a sum of money, and it is all coins. There are 24 more 2-cent coins than 5-cent coins. According to the number of money, the number of 5 cents is 3 jiao more than the number of 2 cents, and there are 53 coins of 1 cent, how many cents is this money?

6.Two years ago, A was 4 times older than B; After two years, A is 3 times the age of B, so how old is A this year?

1.There is a three-digit number, the sum of the digits of each digit is 16, the ten digits are the sum of a digit number and a hundred digits, if the hundred digits and the single digit number are reversed, then the new number is 594 larger than the original number, find the original number. (One dollar one answer).

2.Split 99 into 4 numbers, so that the first number is added to 2, the second number is subtracted by 2, the third number is multiplied by 2, and the fourth number is divided by 2, and the results are all equal, how should I split it?

A team of tractors ploughed a piece of land, ploughed 1/3 of the land on the first day, and ploughed 1/2 of the remaining land on the second day, and then there were 38 acres of land left uncultivated.

2.The three units of A, B and C donated 1.76 million yuan to the Hope Project, and the ratio of the donations was 2:4; 5. Q: How much yuan do each of the three units donate?

3.The three villages of A, B and C jointly build a water canal, and the plan requires 176 laborers, because the population of each village is different, as long as the ratio of 2:3:6 is reasonable, how many laborers are sent by each of the three villages of A, B and C?

4.A middle school held a sports day, and the sum of the number of participants in class A and class C in the seventh grade was three times the number of participants in class B, and the number of participants in class A was 40, and the number of participants in class B was 10 fewer than the number of participants in class C.