Urgent! Help solve a math problem for junior high school, Thanks

Cost (3a+2b).

Revenue (a+b) 2 *5=5(a+b) 2 reams (3a+2b)>5(a+b) 2

Multiply both sides by 22 (3a+2b) > 5 (a+b).

6a+4b>5a+5b

6a-5a>5b-4b

A>B loses money because the average ** of the three fish is greater than the average ** of the two fish later**.

The total ** bought is 3a+2b (1).

The total ** sold is (a+b) 2*5 (2).

If a>b then the total ** bought is greater than the total ** sold.

It's lost.

Because his cost is 3a+2b, the average ** per fish is (3a+2b) 5. It is clear that (3a+2b) 5 is less than (a+b) 2

Let a = 1 and b = 2 1x3 = 3 2x2 = 4 (3+4) 2= A spent a total of 7 yuan to buy fish, and sold it to B to earn money, and he lost money.

That's about it.

Expenditure: 3a+2b

Revenue: 5(a+b) 2

Expenditure - Income = 3a + 2b - 5 (a + b) 2

Losing money means that the expenditure is greater than the income, so a>b

Set the original price to x, the marked price is, and the 20% discount is Li Yingpei let run for x

The profit of 10 times is 2700, then the profit of the argument is 2700 10

The square ridge round is x 270

A pentagon is surrounded by five hexagons, and each vertex is shared by three figures (one pentagon, two hexagons) with x white and y black.

x+y=32;

1 2 6x=5 y, the number of vertices is the same.

Solution, x=12, y=20

abj1202, hello :

The number we commonly use is a decimal number, and the computer program uses only the binary number of the digits 0 and 1 to process data, which can be converted to each other, such as the conversion of binary 1011 to a decimal number should be: 1 2 0 2 1 2 1 2 11In this way, the conversion of the decimal number 6 to the binary number should be 110.

The conversion of 110 to decimal number should be: 1 2 1 2 0 2 4 2 0 6

Converting the decimal number 6 to a binary number should be 110

It can be calculated by short division, because it is inconvenient to write, and you can ask questions if you don't understand.

1.Suppose the son is x years old and the father is y years old.

x-4)*4=y-4

3*(x+4)=y+4

then x=20 y=68

2.According to the mononomial definition, 2m-5=1 3n-2=0 then m=3 n=2 3

If a and b exist at the same time, and there is still a "+" after addition, it is not a monomial, so the exponent of b must be zero, i.e., 3n-2=0, and the exponent of a in the two equations must be equal, i.e., 2m-5=1).

3.( means that the square can't hit b sweat).

From a+b=4 (a+b) =a +b +2ab=16 then a +b =16-2ab (1).

Because (a-b) = 8 i.e. a + b -2ab = 8 (2).

Bring (1) into (2) then 16-2ab-2ab=8 then ab=2

2) 100+(-2) 99=(-2)(-2) 99+(-2) 99=(-2) 99[(-2)+1]=-(-2) 99=-(-2)(-2) 98 Because 98 is even, (-2) 98 =2 98 i.e. original = 2 99

It's a bit messy, I don't know if I understand ......)

m=2 quadratic trinomial, in the cubic of Eq. (a-3) x, the x exponent is 3, which does not correspond to the title, so a-3=0

In Eq. -x m, if the exponent of x is 2, then m=2

The simplified formula is -x 2+2x-2 for quadratic trinomials.

It is recommended that the landlord study more mathematical definition formulas.

1。Daddy 36 Child 12 2. No, it won't. 3 ab=2 4。C 5, I guess. a=3 m=2

1 Set son now x dad now y

Get y=3x

y-4=4(x-4)

The solution is x=12

y=36

1: Solution: Set: The father was x years old 4 years ago, and the son was y years old.

x=4y ①

x+4=(y+4)*3 ②

The process does not need to be written).

x=32y=8

1 Suppose the present son is x years old.

4(x-4)+4=3(x+4)-4

x = 204 (x-4) + 4 = 68 (years).

Answer: Now the age of the son is 20 years old, and the age of the father is 68 years old

1. Let the ages of the father and son be x,y, then the equation (1) x+4=3(y+4)(2)x-4=4(y-4) and then the two equations are binary, that is, x,y