The process of solving the problem of solving the column equation in the second year of junior high

It turned out that there were x people participating.

180\x-2=180\[(1+50%)x]180\x-2=120\xx=30

There were actually 45 people.

There were x people in the dissolution.

180/x=180/x（1+50%）+2

270=180+3x

x = 3030 (1 + 50%) = 45 people.

Forty-five people actually participated.

It was originally planned that x number of people would participate in the voluntary tree planting activity.

The number of people who actually participated in the tree planting activity was x* (1+50%) who originally planned to plant 180 x trees per person.

Actual 180 x* (1+50%) per person

Then there are 180 x — 180 x * (1 + 50%) = 2 to solve the equation to get x = 30 people.

In fact, 30 * (1 + 50%) = 45 people participated in the tree planting activity.

If the original plan is x people, then the actual number of participants = x + 50% x the original plan to plant 180 x per person, and the actual number of people planted per person is 180 x - 2 actual number of people * the actual amount of trees planted per person = 180

Find the original planned number of people, and then find the actual number of people.

If there are x people in the program, you will get:

180 (x+, solution x=30..)

So there were actually 45 people.

If the original plan is for x people to participate, the actual number of participants will be, and the equation can be listed by the title

180, solution x=30, then the actual number of participants is 45.

Solution: If there are x people participating in the original plan, then there are actually people participating, according to the topic.

180\x=180\

Solution x=30

It is tested that x=30 is the solution of the original equation.

Answer: There were actually 45 people participating.

Solution: Suppose there are actually x people participating, and the equation is obtained according to the meaning of the question as:

180÷x+2=180÷50%x

x=90

It takes hours to go.

It is four hours and 42 minutes to come back.

The downhill road is 28x12 60= longer than the uphill road when going

The length of the uphill slope is xkm

x/28+(

Set the annual interest rate of Type A Bond x the annual interest rate Y of Type B Bond

y=x-2 (1)

1000xy=108 (2)

Let the annual interest rate of Type B bond be x.

1000x(x+2%)】xx+1000x(x+2%)=108 is to find out the interest obtained from the purchase of a type A bond for one year, and then multiply this interest by the annual interest rate of the type B bond, and the interest obtained is the interest of the type B bond, plus the principal (the interest earned by the type A bond), that is, 108 yuan. Trust me.

Finally, we use a quadratic function to get x=8%.

Steps: Solve first, in the design, don't talk about it. 1000 multiplied by [x's square] + 20x + 1000x + 20 = 108

x squared + [51 50] xx = 11 125

x+51 100) = 3481 open root.

x+51/100=59/100

The solution yields x=8 100, i.e. 8%.

I think it's very good, as long as you have a little bit of skills, follow my steps, and express it in mathematical language, it's absolutely right. If you don't understand, read it a few times. I finally answered it once, and I hope it can be adopted.

I'm sorry I suddenly remembered yesterday that I didn't add 2% and the final answer should be 10%.

Suppose that x are processed per day, and it takes y days in total, xy=200 5x+(x+5)(y-1-5)=200 to obtain y=10 x=20.

I hope it helps you, and I wish you progress in your studies

Listing a system of equations, assuming that x is processed every day, it takes y days in total, xy=200,5x+(x+5)(y-1-5)=200,y=10,x=20

The two factories A and B can process x and y pieces of new products respectively 1200 x-1200 y=10 per day

y=x=40

y=60

Assuming that factories A and B can process x and y new products respectively every day, then the tool problem is a system of equations: 1200 x +10=1200 yx=

Solve the above equation to obtain: x=60, y=40

A: The two factories can process 60 and 40 pieces of new products per day.

Solution: Let the equation be completed in x days, so A does x days and B does x + 4 days 1 x + 1 (x+4) + (x-1) (x+4) = 1 and multiplies x(x+4) on both sides of the equation at the same time

x+4)+x+x(x-1)=x(x+4)x+4+x+x²-x=x²+4x

x²+x+4=x²+4x

x+4=4x

3x=4x=4/3

The stipulated date is 4-3 days.

Solution: Let the width of the rectangle be x cm, then the length is (x+40) cm, and the diagonal is x+x+40-80=(2x-40) cm, according to the Pythagorean theorem, there is the equation:

x²+(x+40)²=(2x-40)²

2x²+80x+1600=4x²-160x+16002x²-240x=0

x(x-120)=0

x1=120, x2=0 (not on topic, should be discarded) so x=120

A: The width of this rectangle is 120 cm.

1. It takes x days to set up a public operation.

Then 1 (x+18)+1 (x+32)=1 x denominator x(x+32)+x(x+18)=(x+18)(x+32)x 2+32x+x 2+18x=x 2+50x+18*32x 2=9*64 x=24

Therefore, it takes 24 + 32 = 56 days for B to do it alone.

2.Set large and small bottles of soda for each bottle of x and y yuan.

Then 48 x+80 y=26 80 x+48 y=22 let 1 x=m 1 y=n

Then 48m+80n=26 24m+40n=13 (1)80m+48n=22 40m+24n=11 (2)(1)*6-(2)*10 256m=32 m=1 8 substituted (1) n=1 4

So x=8 y=4

That is, the large bottle is 8 yuan per bottle, and the small bottle is 4 yuan per bottle.

1.Let A take x days to complete alone, B to do it alone in y days, and k days to cooperate 1 (1 x+1 y)=k

x=k+18

y=k+32

The solution is x=42 y=56 k=242There are x yuan per bottle of small bottle of soda and y yuan per bottle of large bottle of soda.

48/y+80/x=26

80/y+48/x=22

The solution is x=4 y=8

List a binary equation.

Let A do x every day and B do y every day, assuming that the engineering quantity is 1, then there is:,24(x+y)=1,1-20x=40y, and solving the equation can get 30 days for A and 120 days for B.

In other words, since you want to list the solutions of the equations, then you must have more than binary to have the system of equations, and there is no unary system of equations, so there is no answer that can satisfy you.

1.Let the amount of work to be completed by A per day be x and B is y 24*(x+y)=20x+40y

So x=4y shows that A is dry for one day and B is dry for four days.

There is a second condition: if A alone 20 days, the rest of B will do, and it will take another 40 days to complete the whole project.

B does 40 days, A only needs 10 days, so A does it alone, it takes 30 days.

Take 120 days to do it alone.

In the maintenance project of a bridge, it is proposed to be carried out by A. B: Two engineering teams work together to complete a project. From the information of the two engineering teams, it can be known:

If the two engineering teams work together, 24 days will be the same time to complete the project; If the two engineering teams work together for 18 days, and the first engineering team works separately for another 10 days, the project will be completed. Seek A. The number of days required for two engineering teams to complete the project individually.

Set up two kinds of refrigerators to produce x and y units each this month.

x+y=1000

Solution x=350

y=650

1.If it was originally possible to make x sets, then each set needed 6 x m before material saving, then now each set needs (6 x-1 55) m, and (x+3) can be done to form a set of equations: (6 x-1 55)*(x+3)=6 to get x=30

So now you can do 33 sets.

2.It takes x days for A and y days for B.

Then the velocity of A is 1 x and the velocity of B is 1 y

According to condition 1: (1 x+1 y)*4+1 y *5=1 according to condition 2: x=y-5

The solution is x=10 and y=15

3.Let the speed of each person be V, and let the total workload be 1

then v=1 mn

Now it is m+5 people, the speed is still 1 mn, the workload is 1, and the time required is t then (m+5)*(1 mn)*t=1

The solution yields t=mn (m+5).

4.Assuming that it originally takes t years, the annual development of the land area is v then t*v=360

Now the time is reduced by 6 years, and the area of land developed increases by 2 per year, and the total developed area is considered to be 360, which is (t-6)*(v+2)=360

The solution is t=36, v=10

then the actual development 12

1.Unraveling the original to do x sets.

1/55x=(6/x-1/55)×3

1/55x=18/x-3/55

x=30 or x=-33 x=-33 does not meet the requirements, now the actual 30+3=33 sets.

2.It takes x days for A to be completed alone, and X + 5 days for B.

4 x)+(4 x+5)+(5 x+5)=1 to find x 10

Therefore, A takes 10 days, B uses 15 days, and it takes x days for A to complete alone, and B needs x+5 days 3Set the total amount of work to 1

If M people can complete a project in a day, it can be seen that the daily workload of each person is: 1 AM then add n people, and there are a total of M + N people.

So the daily workload of m+n people is: (m+n) am so it is needed: 1 (m+n) am=am (m+n) day 4Solution: Suppose the actual annual development of x square kilometers.

360/(x-2)=360/x +6

Idea: Since the actual is x, then the planned time for (x-2) per year is equal to the actual time plus six years.

Procedure: Denominator is removed and both ends are multiplied by x (x-2) at the same time

360*x=360*(x-2)+6*x*(x-2)360*x=360*x-720+6*x*x-12*x6*x*x-12*x-720=0

Divide by 6 at both ends at the same time

x*x-2*x-120=0

x-12)(x+10)=0

The solution is x=12, and the other solution x=-10 is rounded.

A: The actual development is 12 square kilometers per year.

Have a nice day.