Math problem, help, hurry up, a math problem, help, now, hurry, hurry

Solution: If the price is reduced by x yuan, it will be sold by 2x more

Set each piece of children's clothing to reduce the price of x yuan, according to the topic of the intention (40-x) (20 + 2x) = 1200, finishing x2-30x + 200 = 0, x = 10, 2x = 20, because to reduce inventory, x = 20

Answer: The price of each children's clothing should be reduced by 20 yuan.

Or solution: If the price of each piece of children's clothing is reduced by 4 yuan, then an average of 8 more pieces can be sold per day, then for every 1 yuan of price reduction, 2 more pieces will be sold, and if the price is reduced by x yuan, 2x more pieces will be sold

Set each piece of children's clothing to reduce the price of x yuan, according to the topic of the intention (40-x) (20 + 2x) = 1200, finishing x2-30x + 200 = 0, solution x1 = 10, x2 = 20, because to reduce inventory, so x=20

Answer: The price of each children's clothing should be reduced by 20 yuan.

or reduce the price of x yuan, then the profit y=(40-x)*(x 4*8+20)=-2x*x+60x+800

1) y=1200, then x=10 or 20

Solution: If the price of each children's clothing is reduced by 4 yuan, then an average of 8 more pieces can be sold per day, then for every 1 yuan reduction, 2 more pieces will be sold, and if the price is reduced by x yuan, 2x more pieces will be sold

Set each piece of children's clothing to reduce the price of x yuan, according to the topic of the intention (40-x) (20 + 2x) = 1200, finishing x2-30x + 200 = 0, solution x1 = 10, x2 = 20, because to reduce inventory, so x=20

Answer: The price of each children's clothing should be reduced by 20 yuan.

1) Set a price reduction of $x. According to the topic: 1200=(20+2x)(40-x) x=10 or x=20 (2) Let the daily profit be y according to the title: y=(20+2x)(40-x)=-2(x-15), add a square + 1250 above the parentheses, so when x=15, the maximum value of y is equal to 1250, that is, when the price of each piece is 40-15=25, there is a maximum profit of 1250 yuan, I Q280246547 don't understand, ask me.

If the price is reduced by x yuan, the profit y = (40-x) * (x 4 * 8 + 20) = -2x * x + 60x + 800

1) y=1200, then x=10 or 20

2) x=15 is priced at 25

1).Set a price reduction of x yuan.

The profit per piece is (40-x) yuan. The number of pieces sold is 20 + 4 x multiplied by 8, and the columnable equation is 1200 = (40-x) (20 + 4 x multiplied by 8) to solve: x = ...

A: ...2）.It is derived from the formula of the one-element quadratic equation in question (1).

Hope it helps you :)

The number of people is an integer, which is equivalent to 6 copies for boys and 5 copies for girls, a total of 11 copies, and only 44 is a multiple of 11 between 40 and 50, then there are 4 people per portion, 24 boys and 20 girls.

The first question calculated that the master painted 120 a day, the apprentice 90, and the room 50, so the third question had to paint 1800, 600 a day

If you hire a master x people and an apprentice y person, then 120x+90y>=600 Simplification gives 4x+3y>=20

To solve by enumeration, you only need to get the smallest y x=3 y=3 or x=2 y=4 for each x

To make 85x+65y a minimum, take x=2 y=4

DE is the perpendicular bisector of AB.

ae = beabc perimeter = ab + ac + bc = ab + ae + ec + bc = ab + be + ec + bc = 26

EBC circumference = BE+EC+BC=18

Subtract the two to give ab=8, which is ac=8

Because de is the perpendicular bisector of ab.

So ae=be

Yes because BE+BC+EC=18

So ae+bc+ec=18

i.e. AC+BC=18

Because ab+ac+bc=26

So ab=8

And because ab=ac

So ac=8

de is the perpendicular bisector, so ae=be

be+ec+bc=18

AE+EC+BC=18

ae+ec=ac

Get AC+BC=18

ab+ac+bc=26 ab=ac

2ac + bc = 26

Solution 1,2 yields ac=8

The selling price per pair is 15% higher than the purchase price. If all are sold, you can make a profit of 120 yuan, indicating that the total cost is 120 15% = 800 (yuan) If only 80 pairs are sold, the difference of 64 yuan is enough to cost, so the purchase price of each pair of slippers is (800-64) 80 = yuan).

Let the purchase price be x, and the total purchase price is y, and the total number of purchases is y, xy(1+15%)=xy+120, 80x(1+15%)=xy-64, and then solve the equation according to the first formula to get xy=800, and then substitute the second formula to get x=8, and then you can also get y=100, so the purchase price is 8 yuan.

Solution: Set the purchase price to be X yuan, then the selling price is, the profit per pair is, and a total of Y pairs are purchased, according to the title

Y = 800 x can be obtained by formula 1, substituted by formula 2, and the solution is obtained: x = 8 Answer: The purchase price of each pair of slippers is 8 yuan.

First, the total price is: 120 divided by 15% = 800 yuan.

Price per pair: (800-64) divided by 80 = yuan.

Price per pair: RMB.

Huh, simple, right?

120/15%=800

A: The purchase price of each pair of slippers is 8 yuan.

Solution: The purchase price of each pair of slippers is X yuan, and the purchase of Y pairs of slippers (1 + 15%) XY = 120 + XY

80*（1+15%）x+64=xy

Simplification xy=800

92x+64=xy

Convert to 92x+64=800

92x=736

x=8y=100

The purchase price of each pair of slippers is 8 yuan.

Solution: I bought x pairs of slippers, and the purchase price was Y yuan per pair.

Then the equation is listed by the title:

80*Solve the equation to get y=8, x=100

So the slippers are priced at 8 yuan.

First, the total price is: 120 divided by 15% = 800 yuan.

Price per pair: (800-64) divided by 80 = yuan.

Price per pair: RMB.

Find the total cost: 120 15% = 800 (yuan).

Find the money for 80 pairs of slippers: 800-64 = 736 (yuan) Find the price of each pair of slippers: 736 80 = yuan).

Seek the unit price of purchase: yuan).

A: The purchase price of each pair of slippers is 8 yuan.

The cost of each pair of shoes is a yuan, and there are a total of B pairs.

Then there are: (1+.)

Solution: a=8, b=100.

That is, the purchase price of each pair of shoes is 8 yuan.

Set the purchase price of each pair to x, a total of y pairs.

then list x*(115%)y-xy=120x*(115%))80 =80*x+64 to solve the purchase ** Yes.

Let the purchase price of each pair be a, then the selling price is set up to enter b double, and the equation can be listed according to the title:

The solution is ab=800 and substituted below.

ab-80* a=8

Set the purchase price of each pair to be X yuan, and the total quantity is Y pairs.

x*y*15%=120

x*（1+15%）*80-x*y=-64

x=8,y=100

I'm sorry, I won't, I'll ask our teacher and I'll tell you next week.

Hello! 2 hours 15 minutes = 9 4 hours.

Then, the distance is 48 9 4 = 108 (km) and the return is 6 km faster than the original, then the speed at the reverse return is: 48 + 6 = 54 (km/h).

Then, having found the distance and speed at the time of return, we can find the time at the time of return: 108 54 = 2 (hours).

Then, divide the sum of the round-trip distances by the sum of the round-trip times, which is: (108+108) (9 4+2) 50 (kilometers per hour) (50 if the whole number is retained, if one decimal place is retained, it is, if two decimal places are retained, it is.)

And the questioner's approach should be wrong, and the unit conversion is wrong.

If you travel 48 kilometers per hour and arrive in 2 hours and 15 minutes, the distance between the two places is 108 kilometers.

The return is 6 kilometers per hour faster than the original, that is, 54 kilometers per hour, so it takes 2 hours to return.

Then the car went from east to west and then to east, and the road it took was 108*2, that is, 216 kilometers. If it takes 2+, which is the hour, then the average speed is 216 divided by it, which is about kilometers of hours.

Wrong unit conversion Let's not talk about the problem of this problem There is a problem with your solution 48 is the speed of the hour, and 135 is the minute, and the 6480 is not the distance, and the problem is the average speed of the round trip, which is the distance of the round trip divided by the time of the round.

It should be 48 108 (48+6)=2h average velocity v=108 2 (2+

The average speed is.

Purely physically, this result is wrong, and it can only be done when the car moves in a straight line at a certain speed.

15 60 = hours).

2 + hours) km) 48 + 6 = 54 (km h).

108 54 = 2 (hours).

2+ hours) hours) A: The average speed of this car round trip is hours per kilometer.

Square volume: 3*3*3=27 (cubic decimeters).

Rectangular base area: 6*5=30 (square decimeters).

Immerse a cube of iron with a side length of 3 decimeters into water, indicating an increase in volume of 3*3*3=9 cubic meters.

Then you are in 9 5*6=

So it rises 3cm

Solution: h=3*3*3 (6*5)=decimeter. It is the volume of this cube = the volume of 6 decimeters long, 5 decimeters wide, and h high.

One: 72 90 162 km h

162km/h＝45 m／s

45×8＝360m

Two: 68 42 = 34 21 m s

520 42 34 21 226 21 m s=1356 35 h three: 75 8 h

It's been a long time since I've done these types of questions, and I've forgotten what to do and I don't know if the answers are right.

l All six faces are perforated is the side area of the six cylinders, plus the area of the cube and the area of the six circles that are deducted.

s = s column side + s positive = 2 * 3, 14 * 1 * 6 + 4 * 4 * 6 = 133,68 (cm squared).