Mathematical solutions the answers should be detailed mathematical solutions

A completes 1 40 per day

According to the title, A did it for a total of 20 days and completed:

B did a total of 10 + 20 = 30 days and completed:

B is done every day: 1 2 30 = 1 60

B is done separately and requires: 1 1 60 = 60 days.

To complete the cooperation between A and B, it takes 1 (1 40 + 1 60) = 24 days.

If the total amount of the project is the unit "1", then the work efficiency of A is 1 40, and if it takes X days for B to complete the project alone, then the work efficiency of B is 1 X, and the equation is:

1) 1 x * 10 + (1 40 + 1 x) * 20 = 1 to get x = 60

That is, it takes 60 days for B to complete the project alone.

2) 1 (1 40 + 1 60) = 24 (days), that is, it takes 24 days for the two teams to complete the project.

1. Set up a B engineering team to complete this project alone for x days.

30/x+20/40=1

x = 602, the time required for the two teams to work together to complete the project 1 (1 40 + 1 60) = 24 days.

A ergonomics: 1 40 B ergonomics: (1 40 * 20) (10 + 20) = 1 60

1) Find the number of days required for engineering team B to complete the project alone.

1 (1 60) = 60 (days).

2) Ask the two teams to work together to complete the project.

1 (1 40 + 1 60) = 24 (days).

Suppose A's velocity is x, B's velocity is y, and the total project is z40x=zz=10y+(x+y)20=20x+30y2x=3yNumber of days required for B = z y=z (2x 3)=40x*3 2x=60 days.

Number of days required for cooperation = z (x+y) = 40x (1+2 3) x = 120 5 = 24 days.

Untie. It takes x days for B to be completed alone, i.e. 1 x. can be completed per day

Column equation: 10*(1 x) +20*(1 40 + 1 x) = 1 Find x as the number of days B completes alone.

Number of days of cooperation between two teams: 1 (1 x + 1 40)=

If B is completed separately for x days, then 1 x is completed per day

10 x + 20 (1 x + 1 40) = 1 gives x = 60....2. The cooperation between the two teams must be 1 (1 60 + 1 40) = 24 (days).

Summary. The condition that every inner angle of a regular n-sided is equal to every outer angle is that n angles are equal. We know that the sum of the internal angles of a regular n-sided is (n-2) 180 degrees, so the degrees of each internal angle are (n-2) 180 degrees n.

The degree of each outer angle is 360 degrees n. According to the conditions given in the question, the degrees of each inner angle should be equal to the degrees of each outer angle, i.e.: (n-2) 180 degrees n = 360 degrees n minus the denominator n, we get:

n-2) 180 degrees = 360 degrees Solve this equation: (n-2) 180 = 360n-2 = 2n = 4 Therefore, when n=4, every inner angle of a regular n-sided is equal to every outer angle.

The condition that each inner beliner angle of a regular n-sided grate is equal to each outer angle is that n angles are equal. We know that the sum of the internal angles of a regular n-sided is (n-2) 180 degrees, so the degrees of each internal angle are (n-2) 180 degrees n. The degree of each outer angle is 360 degrees n.

According to the conditions given in the question, the degree of each inner angle should be equal to the degree of each outer angle, i.e.: (n-2) 180 degrees n = 360 degrees n Cancel the denominator n, we get: (n-2) 180 degrees and front = 360 degrees to solve this equation:

n-2) 180 = 360n-2 = 2n = 4 Therefore, when n=4, every inner angle of a regular n-sided is equal to every outer angle.

Multiply by 4x 2+(4-a)x-a

If there is no item x once.

then a=4

The equation gives 4x+(1-a), x+a, which has nothing to do with x, i.e., -4=1-a, so a=5

=4x²+（4-a）x-a

Then the one-time term is not included, indicating 4-a=0a=4

Rectangle length: 24 3 = 8 (cm).

Rectangle width: 8-3 = 5 (cm).

Rectangle area: 8 5 = 40 (square centimeters).

5m+8n=2

2m-n=3m+n

m=-2n=2

The product of n=-1 algebraic formula -4x to the power of 2m-n y 2 and the product of 3m + n power leakage pure y of the split gear is 5m + 8n.

4 5*x 5*y 2*(1 return to the source 4) 5*x 5*y 2=-x 10*y 4

ab 2=-2 from the question

Because -ab(a 2b 5-ab 3-b)=-ab 2(a 2b 4-ab 2-1)=-ab 2[(ab 2) 2-ab 2-1] is substituted with ab 2=-2 to get:

ab(a^2b^5-ab^3-b)

ab^2[(ab^2)^2-ab^2-1]=-(-2)[(2)^2-(-2)-1]=2[4+2-1]=10

The main thing is that yours has a problem with the formula hehe:

Is it a*b 2=-2 then what is the value of -a*b*(a 2*b 5-a*b 3-b)?

Solution: -a*b*(a 2*b 5-a*b 3-b)=-a*a 2*b*b 5+a*a*b*b 3+a*b*b=-a 3*b 6+a 2*b 4+a*b 2=-(a*b 2) 3+(a*b 2) 2+a*b 2=-(-2) 3+(-2) 2+a*b 2=8+4-2

10. If you want to learn mathematics well, you need to think more and calculate. Mathematics is a subject with strong logical thinking, and only by thinking more can you master it well.

5-2x≥-1

2x≤6x≤3

x-a>0

x>a: If the value of x is an empty set, there is no solution.

Then a 3

From 5-2x -1 to get x 3, it means that x will not be greater than 3, and x-a 0 has no solution, which means that x>a has no solution, so a 3