Summer homework mathematics for freshmen before entering the school

Set up a school and want to buy a colored chalk x box, white chalk y box.

x=(1/6)y

1/6)y+3=(1/5)(y-3)

By y=108

Bring in x=18

A: The school wants to buy 18 boxes of colored chalk and 108 boxes of white chalk.

The total number of the two types of chalk remains the same, the original color accounted for 1 7 of the total, now it accounts for 1 6, just because there are 3 more boxes. So 3 boxes account for 1 6-1 7 = 1 42, then the total is 3 divided by 1 42, which gives 126.

Then the colored chalk turned out to be 126*1 7=18 (box).

Here's how it works, write your own format. The point is that the total number has not changed.

The school originally wanted to buy white chalk x boxes, but then they had to buy colored chalk x 6 boxes.

I actually bought (x 6+3) boxes of pastel (x-3) and white chalk, so there are (x 6+3) (x-3)=1 5 solutions to x=108 boxes.

So the school originally wanted to get 108 chalk 6 = 18 boxes.

Set white chalk to buy x box, colored chalk to buy 1 6 boxes.

The column formula is: 1 6x+x=1 5(x-3)+x-37 6x=6 5x-12 5

1/30x=18/5

x=108So: Colored chalk is 108*1 6=18 (box).

If you write any three-digit number twice and change it to six digits, the six-digit number is 1001 times that of the original three-digit number.

So factoring, this six-digit number.

The original three-digit number is 1001

The original three-digit number *7*143

The original three-digit number *7*11*13

So this number is not only divisible by 7, but also by 11 and 13.

abcabc=abc*1000+abc=abc*1001=abc*7*11*13

Since 1001 is divisible, abcabc is certainly divisible.

Hello landlord. The velocity ratio of A and B is 5:4, so s 4 = s 5

The calculated distance is 160Assuming that the speed of A is 5 and the speed of B is 4, it will take 20 minutes for B to get to B, and 16 minutes for A to B. B stops for 7 minutes, and A departs for 11 minutes. It's exactly 27 minutes.

So A just caught up with B in place B, and it took 27 minutes.

1 850/2000=

2 2πr=20

r=20/π

h=15-20/π

s=2πrr+20h=400/π+300

3 Uh... You're missing numbers.

Anyway to produce tons of 38%.

2t=2000kg.

Then the oil yield is: 850 2000 100 =

If the circumference of the bottom surface is 20cm, the diameter is d=20=, the radius is r=d2=, the height is h=, and the surface area is: s=squared=

Set to squeeze xt beans, squeeze oil yt

Then: 38 x=y

Solve your own calculations, you didn't give it out.

1.Oil yield = oil weight = 850 2000 =

s=2*3.Oil yield = oil weight.

1.Change units first. Oil yield = peanut oil peanuts.

2.Use the radius to find the bottom area of the cylinder, and then multiply the height by the circumference of the bottom surface to find the side area. Add it up at the end.

3.You didn't tell me how many tons of oil to produce. However, it can be found by dividing the amount of oil to be produced by the oil yield.

Solution: Set up large X cans of beverages and small Y cans of drinks.

Column equations: 3x+4y=120 2x+3y=84 2- 3 get:

y=12 substitute y=12

Get: x=24

A: 24 cans of beverages in large pieces and 12 cans of beverages in small pieces.

3 large pieces, 4 small pieces, a total of 120 cans, 6 large pieces, 8 small pieces, a total of 240 cans, two large pieces, 3 small pieces, a total of 84 cans, 6 large pieces, 9 small pieces, a total of 84 * 3 cans, two subtraction.

1 small piece 84*3-240=12 cans.

1 large piece (120-12*4) 3=24 cans.

120-84=36 is 1 large and 1 small.

120-36*3=12 is 1 small.

36-12=24 is 1 large.

Set up x cans for each large piece, and Y cans for small pieces.

3x+4y=120, 2x+3y=84 3 2 get y=12Substituting it to get x=24

The solution is x=24 and y=12

Solution: Set up x cans for each large piece and y cans for each small piece.

3x+4y=120 （1）

2x+3y=84 （2）

Get x 24, y 12

A: 24 cans per large piece and 12 cans per small piece.

Solution: (1) according to the meaning of the topic: (2) according to the meaning of the topic:

ac=10 steps, cd=10 steps, ed=45 steps, bac= cde=90° in bac and cde bac= cde (verified) ac=cd (verified) acb= dce (opposite apex angle) bac cde(asa) ab=de=45 steps and a step about 40cm ab=45 40=1800cm= that is, the distance between Xiao Ming and the tree is about when he is at point A.

Analysis: abc and cde are congruent triangles, ab=de

He has walked a total of 45 steps == de=45-10-10=25 steps, (1) please draw a diagram by yourself;

2) If Ming's step is about 40 cm, the distance between Ming and the tree at point A is =25*40=1000cm=10m

1 (2) according to the title: ac=10 steps, cd=10 steps, ed=45 steps, bac= cde=90° in bac and cde bac= cde (verified) ac=cd (verified) acb= dce (opposite apex angle) bac cde(asa) ab=de Xiao Ming took a step of about 40cm, and walked a total of 45 steps ab=de=45-10-10=25 steps ab=25 40=1000cm=10m That is, the distance between Xiao Ming and the small tree is about 10m when he is at point A