Ask a few junior 2 math questions

Multiple choice If a(a,6) b(2,a) c(0,2) three points are on the same line, then the value of a. (

a, 4 or -2 b, 4 or -1 c-4 or 1 d-4 or 2

Solution: Select a for analysis: Let the analytical formula of the straight line be y=kx+b, and substitute the coordinates of a, b, and c into the analytical formula to obtain three equations: ak+b=6

2k+b=a

b = 2 to solve this system of equations.

Substituting b = 2 into the first two equations gives ak+2=6, 2k+2=a, and substituting the second equation into the first equation gives k = 1 or -2, a = 4 or -2

Answer the question It is known that the image of the proportional function y=k1x intersects the image of the primary function y=k2x-9 at the point p(3,-6).

1.Find the values of k1 and k2.

2.If the primary function intersects with the x-axis at point a, find the coordinates of point a.

Solution:1Substituting the point p coordinates into two analytic equations yields -6=3k1 and -6=3k2-9

Solve these two equations to obtain: k1=-2, k2=1

2.The intersection point of the function with the x-axis, y=0, is substituted into the analytic formula of the function once, and we get: x=9

So the coordinates of point A are (9,0).

Fill in the blank 1(1)If the primary function y=(1-2k)x-k in the morning image y increases with the increase of x, and the image does not pass the second quadrant, then what is the range of values of k?

Solution: Y in the primary function image increases with the increase of x, indicating that the slope is 1-2k>0, and k<1 2; is obtained

The image does not pass through the second quadrant to illustrate the intercept (ordinate of the intersection point with the y-axis) -k<0 to obtain k>0

Therefore, the value range of k is 00

3) Combined with the image of the proportional function y=4x: the range of y values when x>1 (

a y<4 b y<4 c y=4 d y>4

Solution: The image of D2 primary function y=(3m-1)x-m should be selected if it does not pass through the second quadrant, then the range of m

Solution: According to the function image without passing the second quadrant, we can know that 3m-1>0, -m<0, and the solution inequality is composed of: m>1 3

The range of m is m>1 3

Multiple choice question A to answer the question.

1: Because two straight lines intersect p(3,-6), solve the two equations -6=k1*3 and solve k1=-2

6=k2*3-9 Technetium-de-technetiumK2=1

2: Because the primary function intersects on the x-axis, so the y-coordinate=0 so the equation 0=1*x-9 solves technetium-x=9, so the a-coordinate is a(9,0).

Fill in the blank 1: (1)k<=0 (2):k>1 (3):d 2:m<=0Special statement: 100% correct cannot be guaranteed! I hope that some netizens who see the mistake will point out the mistake! Thank you!

Question 1: Calculate 7778*9999+333*6666 (please use the code to calculate simply) 7778*9999+333*3*2222 = 7778*9999+9999*2222 = 9999*(7778+2222) =9999*10000 = 99990000 Question 2: Set a

BC is a non-zero number hunger tolerance, find the absolute value of ab ab + the absolute value of bc bc + the absolute value of ac ac + the absolute value of abc abc |ab/ab| +bc/bc| +ac/ac| +abc/abc| =1+1+1+1 = 4

Reference: me

1.The cyclic section is a three-digit pure cyclic decimal number, which can be rewritten as abc 999, such a form, the sum of the numerator denominator after the reduction is 58, then that is to say, the number after the denominator 999 is less than 58, after the test 999 first divided by 9 the result is 111, greater than 58, and then divided by 3, the result is 37, just to meet the topic, (of course, this result can not be 27, because the denominator is greater than the numerator), then the numerator should be equal to 58-37 = 21, that is to say, the fraction after the reduction is 21 37, the reduced component parent is 999 after the fraction of the molecular formula 567, so abc = 567

2.Think of the goods in a warehouse as unit 1

According to the title, the three of them can be regarded as working together to complete the handling of the two warehouses.

1+1) (1 6+1 7+1 14) = 21 4 hours ......The time for the trio to work together.

1/6） *21/4）= 7/8 ……The amount that A completes within the time of cooperation.

1-7 8) (1 14) = 7 4 hours ......The time of the C gang A.

21 4 - 7 4 = 7 2 hours ......C helps B's time.

1. Pure cyclic decimal abc loop, when written as the simplest fraction, the sum of the numerator and denominator is 58, then the three-digit number abc=

Answer] The way to write cyclic decimal is abc 999

The sum is 58, so the decimal can be divided.

The factor of 999 is 3,3,3,37, because the sum is 58, so the denominator can only be 37 and 27, because it is a true fraction, the numerator is less than the denominator, so the numerator is 58-37 = 21, and the denominator is 37

The score was 567,999

This pure cyclic decimal is.

Three-digit abc = 567

2. Two same warehouses, after handling the goods in one warehouse, it takes 6 hours for A, 7 hours for B, and 14 hours for C. A and B each start to move goods from one warehouse at the same time. At the beginning, C first helped A to carry the goods, and then to help B carry them, and finally the goods in the two warehouses were moved at the same time.

Then C helps A for hours, C helps B for hours?

Answer] If the total amount of goods in each warehouse is 1, then the total amount of goods in the two warehouses is 2, regardless of whether C helps A or B, A, B and C have been working at the same time.

The ergonomics of A, B and C is 1 6 + 1 7 + 1 14 = 8 21 After the three people move two warehouses, they share the time:

2 (8 21) = 21 4 hours.

A moved, 21 4 1 6 = 7 8

B moved: 21 4 1 7 = 3 4

C and A moved: 1-7 8 = 1 8, time spent: (1 8) (1 14) = hours C helped B moved: 1-3 4 = 1 4, time spent: (1 4) (1 14) = hours.

Just a few words about the first question: (none of them say why) Let x= abc......,1000*x - x=abc is interesting, just move the decimal point, hahaha.

1. According to the meaning of the title, it can be known that the point p may be outside the circle, on the circle, or within the circle, so it cannot be determined

Solution: Pa= 3, the diameter of o is 2

There are three cases of the position of the point p: outside the circle, on the circle, inside the circle 2 Knowing that a is a point on the circle o, the radius of the circle o is 1, and there is another point p on the plane, pa = root number 3, so what is the relationship between the point p and the circle o?

Answer: The distance between the center of the circle o and the point p is 1 + root number 3.

Knowing the point A b and the line L, make a circle so that it passes through points A and B, and the center of the circle is on the line L.

1 When the straight line l is not perpendicular to the straight line ab, how many circles can be made?

2 How many circles can be made when the line L is perpendicular to the line AB but does not pass through the midpoint of AB?

3 When the line L is the perpendicular bisector of the line segment AB, how many circles can be made?

A: 11 pc;

2.0 pcs.;

3.There are infinitely many of them.

That's not hard, 1If so, then 3948 is to the seventh power

Because 3948 is a hundred times his square, and his square is ten thousand times his, which is four more zeros. That's 3+4=7 power.

Please use the formula to express the sum of squares of the first n positive integers as 1 6xnx(n+1)x(2xn+1).

That's a formula: the formula is: n*(n+1)*(2n+1) 6.

Calculation: 21 +22 +23 +24 +....40 We can calculate the square of 1 to 40 and subtract the square of 1 to 20.

The square of 1 to 40 is: 40*41*81 6=221401 to 20 squared is: 20*21*41 6=2870 so calculate:

21²+22²+23²+24²+…40 = 22140-2870 = 19270 thank you.

7 times because the square of 3948 = the square * the square of 100.

The sum of squares of n positive integers is 1 +2 +3 +4 +....n²=1/6n（n+1）(2*n+1)

3948²=（100×

1/6×n(2n+1）（n+1)

So 21 +22 +23 +24 +....40 is equal to the first 40 minus the first 20.

2.1 of the second + 2 of the second + 3 of the second + ...Quadratic of n = 1 6 n (n+1) (2 n+1).

1 times 10 to the power of 7.

2 questions will not.

1. The worker master cuts four circles from a piece of scrap iron sheet to make an impact pad, and requires the area of each circle to be, so how many centimeters is at least the side length of this iron sheet?

The diameter of the circle = 2* (4*2=8, the side length of this iron sheet is at least 8 cm2, (1) If the edge length of the cube is 1, then the volume is 1, if the edge length of the cube is 2, then the volume is 8, if the edge length of the cube is 4, the volume is 64, if the edge length of the cube is 8, the volume is 521, when the edge length is 2n, what is the volume?

When the edge length is 2n, the volume = 2n * 2n * 2n = 8n 3 (2) The volume of a cube is 1, then its edge length is 1, the edge length is cubic root number 2 is, the volume is 3, and the edge length is cubic root number 3....If the volume is expanded to n times, how many times will the edge length be expanded?

If the volume is enlarged to n times of the original, the edge length is expanded to n times that of the original cubic root number.

1, r2 = r= 2 becomes at least the diameter of two circles, i.e., 8

2. (1) The volume of the cube = the cubic of the edge length So when the edge length is 2n, the volume is 8n3

2) Triple root number n

1.[(x + root number 2) (x - root number 2)].

2.(x+root2)(x-root2)(x-root2).