Ask someone to do me a few math problems in the first year of junior high school, and don t come if

1.丨a-2丨+丨b+half丨=0 gives a=2, b=-half, then b+a-half=1

One-eighth + two and two-quarters - eight and seventy-three and one-half of eighths = -2-1 2-1 8+2+1 2-8-7 8-6-3 4-13-1 2=-29 and a quarter.

丨a丨+a must be a non-negative number.

6.丨17-54丨=37

With 24 + 12 + 6 + 3 + 1 = 46, you can drink up to 46 bottles of this beer.

1) d first remove the absolute value symbol The original formula = a-2 + b + half = 0, that is, a + b - three halfs = 0 Add 1 on both sides at the same time, so a + b-1 2 = 1

2) Let me tell you first, my 1 8 is the meaning of one-eighth, and the same is true for other numbers

First of all, 2 and 2 4 = 20 8, 8 and 7 8 = 71 8, 13 and 1 2 = 108 8

So the whole equation is =-20 8-1 8+20 8-71 8-54 8+108 8=-18 8=-9 4

3) The smallest positive integer is 1, the largest negative integer is -1, and the rational number with the smallest absolute value is 0, so it is d

4) c is a positive number when a>0, and when a= or <0Yes 0

6) 17-54=-37 The absolute value is 37

8) The price of a case of beer = 12 * 5 = 60 120 60 = 2 (120 yuan can buy a hatchback) 2 * 12 2 = 12 (you can also take an empty bottle to exchange for 12 bottles) 12 2 = 6 6 2 = 3 The last 3 bottles can also be exchanged for a bottle One bottle and the remaining bottle can be replaced with another bottle So a total = 24 + 12 + 6 + 3 + 1 + 1 = 47

And you said above, I don't have a book, so I can't help you do it

Be concise and to the point with my demeanor!

1 d2 Press the computer yourself.

3 d4 c

1 d2 didn't look.

3 b4 c

After that, it's too simple to count yourself, and the last one is 24 + 12 + 6 + 3 + 1

A:xB:y

C: z12(x+y)=24z

9（y+z）=24z

x=1/3z

y=5/3z

A: 72 days.

B: 72 5 days.

C: 24 days.

B: 72 5 * 500 = 7200

C: 24*800=19200

Let the efficiency of A x, B y, C z

x+y=1/12

y+z=5/72

z=1/24

Solution A alone 18 days, B 36 days, C 24 days.

Multiply by the daily charge, with B charging the least.

The sum of the inner angles of an n-sided is (n-2)180 and the outer angles of an inner angle are less than 180

So the maximum multiple of 180 in the range of 600 is 540 540 180 = 3 n = 2 + 3 = 5

The polygon is five deformations.

This means that the outer angles of this polygon are 80 at the largest and 40 at the smallest, and the difference is the same degree.

With n sides, then the outer angles and (80+40)*n 2=360 n=6

The inside angle of a regular 7-sided polygon is 180-(360 7) and the inside angle of a regular triangle is 60

Let n deform then 360-180+360 7 -180+360 n is a multiple of 60 and.

360 7 + 360 n is a multiple of 60.

60*6*(n+7) 7n 6*(n+7) 7n is an integer n=424 edges.

1. (n-2)*180<=600-x,x<180,(n n,i.e. 3,4,5......The unique solution n=5, x=60 is obtained, and the polygon is a 5-sided polygon;

2. According to the summation theorem of the inner angles of the polygon and the summation formula of the equal difference series, it is solved from the known (n-2)*180=(100+140)*n 2, and the polygon is 6-sided;

3. Don't know what the question requires to solve?

4. List (n-2)*180<270+90 according to the question, and get n<=4, with a maximum of 4 edges.

1. According to the formula of the sum of the inner angles of the polygon, the sum of the inner angles of the polygon is 180*(n-2), where n is the number of sides. In the problem, the sum of the inner and outer angles is 180, and the difference between the two is between 0 and 180. Therefore, the difference between the sum of the internal angles and 600° of the polygon is between 0 and 180.

Therefore, the eligible n is 5 or 6. The sum of the inner angles of the pentagon is 540, and the hexagon is 720. For pentagons, the chosen interior angle is 60°.

For hexagons, the chosen internal angle is 150°.

2. According to the summation formula of the equal difference series: (100+140)*n 2=180*(n-2), the solution is: n=6

3. The inner angle of the regular heptagon is 900 7 °. The inner angle of the regular triangle is 60°. and is 360 °, i.e. 2520 7.

Therefore, the eligible polygon is the solution of the following equation: 180*(n-2) n=1200 7,180*(n-2) n=780 7,180*(n-2) n=360 7And because n is a positive integer, only the first equation has a positive integer solution, and the answer is n=42.

4. The n-sided shape that satisfies the condition has n-3 acute angles, and the sum of the acute angles is between 0 90 * (n-3). The sum of the three obtuse angles is between 270 540, so the sum of the internal angles is 180 * (n-2) satisfies 270< 180 * (n-2) < 90 * (n-3) + 540. Solving this inequality yields n<7, i.e., a hexagon at most.

The absolute value sign is non-negativity, i.e., |x+(3 and 1 2)|with |y-(1 1 3) |Greater than or equal to 0

And because |x+(3 and 1 2)|with |y-(1 1 3) |The sum is equal to 0, so both terms are 0

Then simplify, x+3 and half = 0, so x=-(3 and half) y-1 and one-third = 0, so y=1 and one-third 2xy=-2*(3 and one-half) *1 and one-third) and then the answer comes out minus 9 and a third or minus 28.

Because the sum of two numbers that are opposite to each other is 0, x+(3 and 1 2)|y-(1 1 3) |=0 then x+(3 and 1 2)=0 ,x=-7 2,y-(1 and 1 3) =0, y=4 3

2xy =-2×7/2×4/3=-28/3

Because two numbers are opposites of each other, and both numbers contain absolute values, both numbers are 0. So x 7 2, y 4 .

-28/3

It seems to be. Is it greater than 0 or less than 0 in the absolute value?

|x+(3 and 1 2)|with |y-(1 1 3) |are inverse numbers to each other.

Then x+(3 and 1 2)=0=>x=-(3 and 1 2)=-7 2y-(1 and 1 3)=0=>y=(1 and 1 3)=4 32xy=-(9 and 1 3).

Solution: From the meaning of the question: x+3 and 1 2=0 y-1 and 1 3=0

So x=-7 3 y=4 3

So 2xy = 2 -7 3 4 3 = -56 9

1 All (1) - 1, 2, -4, 8, -16, 32, -64 ,..Q: What is the 2009th number?

The opposite number of the 2 square of 2008.

2) Known |a-1|+(b+2) to the power of 2 = 0, find the value of (a+b) to the power of 2009.

Analysis: a-1=0 b+2=0

a=1，b=-2

a+b) to the power of 2009 = -1

3) Known | x |=8，| y |=2/3 and xy 0, find the value of x out of y.

Analysis: xy<0 x= 8, y= 2 3 when x<0, y>0

x/y=-12

When x>0, y<0

x/y=-12

Set the water velocity to x km/h.

10（12-x)=6(12+x)

120-10x=72+6x

16x=48

x = 3 water velocity is 3 km h.

Let the water speed be x km/h.

then the downstream velocity is (12+x) kilometers.

When the speed against the water is (12-x) km.

12+x)*6=(12-x)*10

16x=48

x=3, so the water velocity is 3 km.

Set the distance to be x km.

Then the velocity of the water is x 6 and the velocity of the reverse water is x 10

x/6+x/10)/2=12

x/6+x/10=24

x=90 downwater speed = 90 6=15 km/h.

Water velocity = 15-12 = 3 km h.

The current speed is 3 km h and the distance between the two piers is 90 km.

Let the speed of the water flow be x kilometers per hour, and the distance between the two banks is a kilometer.

a/(x+12)=6

a/(12-x)=10

The solution is a=90x=3

Negative indices can be replaced with positive indices first, e.g. 3 -2=(1 3) 2, and negative indices can be replaced with the reciprocal of the base. (3x+2y+4)(5x-2y-1) to be multiplied one by one.

3x*5x+3x*（-2y）+3x*（-1）]+2y*5x+2y*（-2y）+2y*（-1）]+4*5x+4*（-2y）+4*（-1）]

a-b)(a 2+ab+b 2)+b 2(a+b)-a3 should be simplified before substitution.

a^3+a^2b+ab^2-a^2b-ab^2-b^3+ab^2+b^3-a^3=ab^2=（-1/4）2^2=-1

x+1 x=4, find: x 2+1 x 2 is there a square relationship.

x+1 x) 2=x 2+2+1 x 2=4 2=16 can be solved to get x 2+1 x 2=16-2=14

a-b) 2·(b-a) 3·(a-b) -4.

a-b)^2[-（b-a)^3]（a-b)^-4= -（a-b)^(2+3-4)= -（a-b)^1=b-a