I don t understand the math questions, I have an exam tomorrow, ask for a master!

The first question and the second length of the rope are long. Because the length of the second section is two-thirds of the total length, the length of the first section of rope is one-third of the total length, and two-thirds is greater than one-third, so the second section is long.

Question 2: There are a large number of boys. Four fifths is equal to 80%, 85% female 80% male, because this is an equation, that is to say, 85% * number of girls = 80% * number of boys, because 85% 80%, so the number of girls number of boys, so there are more boys.

Completely hand-hitting, looking

1. Two-thirds of the length is longer, because it's two-thirds the length of the rope, and two-thirds of a meter is only one-third of the length of the rope.

One. 2.More boys Four-fifths are 80%, 85% is greater than 80%, 80% of boys = 85% of girls So there are more boys.

The above answer is correct! I don't have to write it! I didn't want to, but I can't cancel it!

1. A rope is knotted into two sections, and the second section is two-thirds of the total length; Then the first paragraph is one-third of the full length, so the second section is long.

2. The number of girls multiplied by 85% is equal to the number of boys multiplied by four-fifths (80%) so there are more boys.

The second section of the rope is long, and the title clearly says that the second section is two-thirds of the total length, then the first section is one-third of the total length, 2 3 > 1 3

If there are more boys, four-fifths = 80%, 80% of boys = 85% of girls, 80% < 85%, then the number of boys is more than the number of girls, so that the product of the two can be equal.

The second Wang Qi question.

You can set it to x grams, then.

1/5x-1/7x=80

2/35x=80

x=1400

So x = 1400 grams, which means that the cake is 1400 grams.

I don't understand the first question either.

The first problem is that there is one-fifth left, that is, one-half of the aged vinegar is one of the five-point resistance to the leakage difference when it is full. The old vinegar accounts for two-fifths of the full time, and how many kilograms depends on how many kilograms it is.

( ) and 9 are coprime numbers, their greatest common factor is (1), and the least common multiple is (their product).

Note: The number that can be filled in at the beginning of this question is not unique, for example, it can be filled in, etc.

2.The largest cone is made from a cylindrical piece of wood, and the volume of the shaved part is 8 cubic decimeters, and the volume of the cone is (4) cubic decimeters.

3.The reciprocal of (c) is greater than the original a. The natural number b. False score c. A number that is larger than 0 and smaller than 1.

4.Rectangles, squares, and circles with equal circumferences have the largest area (circle).

Solve the equation: Solution: 5x

5x＝10x＝10÷5

x 2 columnar calculation: 35 of a number is 15 less than half of this number, find this number.

Application Questions:1An iron cone was submerged in a cylindrical measuring cup with a base area of 62 cm (the water did not overflow), and the height of the water rose by 2 cm. If grams of iron weigh per cubic centimeter, how many grams does this iron cone weigh?

62 2 grams.

2.Xiao Ming's father deposited 4,500 yuan in the bank last year for two years, and planned to donate the interest to support Hope Primary School. If the interest rate for two years is 20 yuan after deducting interest income tax, how much is the take-home interest of Xiao Ming's father?

4500 RMB.

I hope it will help you in your studies, if you don't understand any questions, please feel free to ask!

I don't remember some of the formulas, what is the formula for finding the volume of a cone?

According to the principle of equal volume.

The forged piece of steel is x meters long.

x=x=

The forged square steel is x m x m x = long

The forged square steel is x meters long.

x=x=

The machine tool factory produced 144 machines in September, 24 units more than planned, how many percent of the overproduction?

Xiao Ming's weight is one-fifth lighter than his mother's, and his father's weight is three-fifths heavier than his mother's, how many percent of Xiao Ming's weight is his father's?

Reasonable. The original formula can be simplified.

x²-4x+4)/(x²-4）÷（x²-2x）/（x+2）-（1/x）+1

x-2)²/(x-2)(x+2)÷x(x-2)/(x+2) -1/x）+1

1/x）-（1/x）+1

1 As long as x is not equal to 0, 2, -2, then the above equation is meaningful.

That is, if x is not equal to 0,2,-2, (x -4x+4) (x -4) (x -2x) (x+2)-(1 x)+1=1

Therefore, Cong Cong's belief that x, as long as any value that makes the original meaningful is substituted, will have the same result, it is obviously correct.

(x -4x+4) (x -4) (x -2x) (x+2)-(1 x)+1 (x -2x) (x+2) Do you need to add parentheses in your title should be (x -4x+4) (x -4) (x -2x) (x+2))-1 x)+1 like this, so you can reduce and dissolve to get 1, any number is one as long as it is meaningful, so Cong Cong's statement is correct.

Divide as follows: (x-2) ((x-2) (x+2)x)) multiplied by x-1 x+1

x²-4x+4=（x-2）²;x²-4）=（x-2)（x+2）;x²-2x=x(x-2)

Reasonably, this algebraic formula can be simplified, (x-2) (x-2)(x+2) x(x-2) (x+2) -1 x)+1=(1 x)-(1 x)+1=1.

Therefore, this equation is equal to the same result as long as any value is substituted to make the original meaningful.

Makes sense, because this algebraic simplification results in 1So no matter what value x takes, the result is the same.

Reasonable! As long as x is substituted for any value that makes the original meaningful, it will have the same result 1, regardless of x.

Makes sense. Algebraic simplification is always equal to "1", independent of the value of x.