Math problems will not be, emergency support, math problems emergency help

Natural numbers (the fourth and sixth floors are wrong).

Negative numbers: -78, -21

Even number, -78

Odd Prime (31 is also a prime number!) ）

Composite number, -21

"2 ml" means that the actual capacity is 2 ml less; "550 ml (+5 ml)" means "550 ml of mineral water, with an error between +5 ml, i.e. 550 555 ml."

Excuse me. I'm also bad at math.

In %21, seven hundredths, and 31, there are natural numbers (2,6,5,51,31), negative numbers (-78,-21), even numbers (2,6), odd numbers (5,51,31), prime numbers (2,5,), and composite numbers (6), and composite numbers (6).

The volume of Star Mineral Water is 55 ml, and the actual capacity measured in the sampling test is more than 2 ml, which is recorded as +2 ml, so what does -2 ml mean? Mineral water made with the following label "550 ml (+5 ml) Did you know? -

Then -2 ml means 2 ml less, and the label "550 ml (+5 ml)."

Yes, you need to do this kind of thing.

Natural numbers have (51), negative numbers have (-21), even numbers have (-78), odd numbers have (31), and composite numbers have (78).

"2 ml" means that the actual capacity is 2 ml less.

550 ml (+5 ml)" means "550 ml of mineral water with an error between +5 ml".

Let's do it yourself, kid, I don't want to hurt you.

Solution: (1) Because the equation x 2-4x+m 2-2m+5=0 has a real solution.

Therefore, it can be reduced to (x-2) 2+(m-1) 2=0, so we get x1=x2=2 , m=1, and because the lengths of ab and ac are 5 times that of the two roots of the equation respectively.

So both ab and ac are 10 in length

2) Because tan aco= 3 4, the vertex of abc is on the coordinate axis, so aoc is a right triangle, let oc=x then ao=3x 4 by x 2+(3x 4) 2=10 2

Get x=8 or x=-8 (rounded).

So the coordinates c(8,0) b(-8,0) a(0,6) because p is the midpoint of ab.

So p(-4,3).

Analytic formula for straight lines passing through c and p points:

y-3) (x+4)=(0-3) (8+4) i.e.: y=

3) If PM oc and pm=oc, then M=P+OC or M=P+Co=P-OC [the above formula refers to the addition of coordinates, oc is a vector, (8,0)] point m(4,3) [ac midpoint].

or m=(-12,3).

If om pc and om=pc

then m=o+pc or m=o-pc [pc(-12,3)] point m(-12,3) [ac midpoint].

or m=(-12,3).

If cm op and cm=op

Then m=c+op or m=c-op [op(-4,3)] point m(4,3)[ac midpoint].

or m=(-12,3).

To sum up: the coordinates of m are (4,3) (12,3) (12,-3).

(1) The original equation is transformed into the sum of two perfectly flat forms, so as to find the two roots of the equation, and further find the length of ab and ac;

2) According to the trigonometric function, the coordinates of c and p points are first obtained, and then the linear analytic formula of c and p points is obtained by the method of undetermined coefficients;

3) There are four coordinates of point m

Answer: Solution: (1) Method 1:

x2-4x+m2-2m+5=0，x-2）2+（m-1）2=0

x=2，m=1，x2-4x+4=0，x1=x2=2

ab=ac=10

Method 2: The equation has a real root.

=-（m-1）2≥0

m-1) 2 0 and (m-1) 2 0

m=1x1=x2=2

ab=ac=10

2）ycp=-49x+83

3) M1 (3,4),M2 (9,-4),M3 (-9,4) Comments: This question is difficult, and the comprehensive examination of functions, equations and other knowledge is conducive to cultivating students' research spirit and perseverance

1) There are 3 options for the first singles, since one person cannot play two singles, so there are 2 options for the second singles, and since everyone has to participate in the tournament, one person in the doubles is the one who does not participate in the singles, and there are 2 options for one doubles player outside the two, so there are a total of 3 2 2 = 12 different lineups.

2) The probability of winning two sets in a high year is 3 (3 7) (3 7) (4 7) = 108 343;

The probability of winning three sets in the first year of high school is (3 7) (3 7) (3 7) = 27 343;

Therefore, the probability of winning at least two sets for the senior team is 108 343 + 27 343 = 135 343.

3) The probability of losing doubles and singles in the first year of senior high school is (4 7) (4 7) (4 7) = 64 343;ξ=0;

The probability of losing a singles match in the first year of high school is 2 (3 7) (4 7) (4 7) = 96 343;ξ=2;

The probability of losing two singles games in the first year of high school is (3 7) (3 7) (4 7) = 36 343;ξ=4;

The probability of winning a doubles match in a senior year is (3 7) (4 7) (4 7) = 48 343ξ=3;

The probability of winning a doubles match in a single game is 2 (3 7) (3 7) (4 7) = 72 343;ξ=5;

The probability of winning two games in doubles and two in singles in the first year of high school is (3 7) (3 7) (3 7) = 27 343;ξ=7;

So the distribution of the upper grade scores is listed as:

p 64/343 96/343 48/343 36/343 72/343 27/343

From the question, we know the point c(0,1).

Let the parabolic equation be y=ax 2+bx+c

The axis of symmetry x=-2b a=o, a=0 then the curve is a straight line, so the intercept of b=0 on the y-axis = c=1

Since fg=2, let f(4,2) be substituted into the equation to get a=1 16

So the equation is y=(1 16)x 2+1

A on the left is a=(-2,y).

Substituting the equation yields y=5 4

So ad=5 4

1) From the problem, we know that the point c(0,1) lets the parabolic equation be y=ax 2+1, and fg=2, so assuming that the f point is on the right, then f(4,2) is substituted into the equation to get a=1 16, so the equation is y=(1 16) x 2+1(2), assuming a is on the left, then a=(-2,y) is brought into the equation to get y=5 4, so ad=5 4LZ is not kind, it is obvious plagiarism.

1、y=500-10（x-50）

y=1000-10x (50=x 100)2, the sales unit price should be set at x yuan.

x-40) (1000-10x) = 8000 solution: x=60 or x=80

(1) y=500-10(x-50) (100>x≥50)

2) Let the profit be z, then the relation about z is z=(x-40)y=[500-10(x-50)](x-40), (y<250) can get a range of x, i.e., x>75, and then the equation about x, z=8000, and the solution is the answer.

After the point d is made as the parallel line of ab intersects ae at f, and df= is obtained from the known condition of Xiao Ming; Extending the Cd to Ae to G, ab=20 can be obtained from Xiaohua's condition

Solution: (1) It is obtained by working weight = work efficiency time:

w t=1600 (t>4,w<400): w=1600 t (t>4,w<400) (2) Set up a garment factory to make x T-shirts every day to complete the task.

Obtained by working weight = work efficiency time:

x×(t-4)=1600

Answer: The function relation is w=1600 t ,(t>4,w<400);

How many t-shirts do garment factories have to make every day to complete the task.

Hope it helps you)

Produce W pieces every day, if you produce 2 days, it is 2W pieces, and so on, T day is TW pieces. There are a total of 1600 pieces, then TW is equal to 1600

tw=1600

Both sides are divided by t

w=1600/t

This is the function of w and t.

Column-function relationship, pre-column relation, which one is the independent variable, both sides are divided by this letter.