I can t do math problems, so I ll ask you for advice, and there will be rewards

Application question: %:x=4:5

So basketball accounts for x=35%.

So there are 35 of them in basketball.

2. Set the full length to x

x/4+30%x+900=x

x=2000

Multiple choice question: After facing a rectangular paper 3 times, you can get 8 small square papers, so the area of each small square is one-eighth of the area of the original rectangular shape, that is, so choose C to fill in the blanks:

Fire = 125% v gas.

v fire = 125% 64 = 80

pcs) 28 * 4 5 = 35 pcs.

1/1 - 3/10 = 9,900/20 9/20 = 2000 (m) Choice: a Then, grams of salt.

80 km. Some may not be right, please forgive me).

28% = 28 (pcs) 28 4 5 = 35 (pcs) Answer: There are 35 basketballs.

2. Solution: Set the channel length to xm, according to the topic

x(x=2000 A: The channel is 2000 meters long. 3：c

100* blue balls.

25% c125% 80 kmh.

1,100x28%=28pcs 4 5=28 Basketball Basketball Balls = 35pcs.

2 Set the total length x meters, and obtain 1 4x+3 10x+900=x to obtain x=2000 meters.

Multiple choice question 1 c

1. 100 times equals 28, which is the number of red balls. Let the basketball have x then 28:x=4:5 solve x=35 2,

1.Solution: Red balls: 100 28%=28 (pcs).

The ratio of red balls to blue balls is 4:5

The number of blue balls is: 28 4 5 = 35 (pieces).

There are 100*28%=2835 red balls and 28*5 4=35 blue balls.

Set the total length x x-x 4 -30% x = 900 x = 2160 and choose c6g

LZ is really good at finding a way to help children do questions here.

1.To determine the sugar yield of sugarcane is to find the weight of sugar in the total weight of sugarcane. ( Right) 2Because the numerator of the percentage can be an integer or a decimal greater than 100, the percentage can be found at most than 100%. (Right).

3.There are 97 products qualified and 3 unqualified, with a pass rate of 97%. (right)4

When 2 kg of sugar is dissolved into 50 kg of water, the sugar content of the sugar water is 4%. (False) Application Questions: 1

The sugar mill processed 7,200 kilograms of sugar in May, using 60 tons of sugarcane to find the sugar yield of sugarcane.

Note that the name of the unit) 7200 (60 1000) = 12%2There were 40 freshmen who practiced shooting live ammunition, each firing 3 bullets, and the result was 100 rounds.

3. A sugar factory uses tons of sugarcane to extract sugar, and the slag is 2112 kg. Find the sugar yield of sugarcane.

True or False Fill in () for true or false questions:

1.The sugar yield of sugarcane is to find the weight of sugar in the total weight of sugarcane. （2.Because the numerator of the percentage can be an integer or a decimal greater than 100, the percentage can be found at most than 100%. （

3.There are 97 products qualified, 3 are not in line with the silver standard, and the pass rate is 97%. （4.Dissolve 2 kg of sugar into 50 kg of water, and the sugar content of Feng and Peng sugar water is 4%. （

Let the original speed be x and increase the speed by 20% after speeding up, and the speed will be (1+20%) x the original time required is 510 x

But this time it takes 3+30 60+(510-3x) [(1+20%)x] as scheduled, i.e.

3+30 60+(510-3x) [(1+20%)x]=510 x.

Let the original velocity be x

510/x=3x+

Too lazy to understand.

Solution: There are x white blocks, then.

From the meaning of the title 3x=12*5

x=20, so there are 20 white blocks.

12 black blocks, 12 5 sides = 60 sides.

The white block has 6 sides, 3 of which are connected to the white block, so there are 3 sides connected to the black block.

Seven out of nine.

It is not correct to divide by four-thirds and seven-nines by three-quarters of the same result and meaning.

Because the meaning of 7 9 4 3 is to know that the 4 3 of a number is 7 9, find this number. The number of known parts is the total.

The meaning of 7 9 3 4 is to find out what is 3 4 of 7 9. The known total is found in parts.

7 9 4 3 = 7 9 3 4, they are calculated the same.

So the meaning is different, and the calculation result is the same.

The result is the same, the meaning is not the same, one is the division rule and the other is the multiplication rule, although the division in the conversion process is converted to multiplication to calculate the result, but in the end it follows a different definition

(Right).Although the concepts of multiplication and multiplication are different, dividing by a number is the reciprocal of multiplying a number, so both the front and the back are multiplied.

After reading the questions, the sorting conditions can be found.

The main principle is that the line segment between two points is the shortest, and the perpendicular line segment from the point to the straight line is the shortest.

The main idea is to equate BM+MN to a straight line segment.

Solution: Find a little e on the AC edge so that ae=an and connect EMBecause ad is the angular bisector of the bac.

So me=mn (equivalent to moving point n to point e to solve).

Finding the minimum value of BM+MN is the minimum value of BM+ME.

Because m and n are the moving points on ad and ab respectively, the perpendicular line of ac is crossed by b and ac is crossed at f point (emphasis added), bf is the minimum value of bm + me, that is, the minimum value of bm + mn.

and ab=4 (the second under the root number) bac=45° bfa=90°

So bf=ab=4

That is, the minimum value of BM+MN is 4.

If m is taken as the fixed point first, then mn is the smallest mn ab

Set me ac

ad is the bisector of bac.

me=mnIn bme, if bm+me is minimal, then b, m, and e are in the same straight line be ac

and bac=45° ab=4 2

be=4 i.e. the minimum value of bm+mn is 4

In the acute triangle ABC, ab=4 2, BAC=45°, the bisector of BAC intersects BC at D, m, and n are the moving points on AD and AB, respectively, and the minimum value of BM+MN is obtained.

Solution: abc is an acute triangle, a=45°, 45°b n (the sum of the two sides of the triangle is greater than the third side), > nb (the hypotenuse is greater than the right angle)=4, so it is proved.