A math equation problem, thank you, help me solve a math problem with equations .

Regardless of the construction time, from the perspective of cost saving, Company B should be selected to complete it alone.

The reason is: calculated by the following example:

1. It takes x days and weeks for company A to complete it alone, and it takes y days and weeks for company B to complete it alone.

6/x+6/y=1

4/x+9/y=1

1/x=a 1/y=b

12/x+12/y=2

12/x+27/y=3

15/y=1

y=156/x+6/15=1

6/x=1-2/5

6/x=3/5

30=3xx=10

It takes 10 weeks for A to complete alone, and 15 weeks for B to complete alone.

2. Weekly wages are required, and A is M million yuan, and B is N million yuan.

6m+6n=

4m+9n=

12m+12n=

12m+27n=

15n=4n=4/15

6m+6×4/15=

6m+24/15=

6m=6m=

m = weekly wages, set A is 10,000 yuan, B is n thousand yuan.

A needs to be paid to complete it alone: 10,000 yuan).

B needs to pay for completing alone: 4 15 15 = 4 (10,000 yuan), so from the perspective of cost saving, company B should be selected to complete it alone.

Featuring x sets of costumes; Scheduled to be completed on y days, 20y=x-100

1）23y=x+20

2) Obtained from (1).

x=20y+100 substitution (2).

23y=20y+100+20

3y=120

y=40x=20*40+100=500

So the task of this batch of costumes is 500 sets; It was originally scheduled to be completed in 40 days.

The second formula subtracts the first formula and divides the two sides by 2 to get 4a+b=-1, and the third formula subtracts the first formula and divides the two sides by 3 to get a-b=6

The addition of the above two equations yields a=1 and then yields b=-5

Substituting the conditional first formula yields c = 6

In summary, a=1, b=-5, c=6

1), 2), 3) respectively.

2)-1):8a+2b=-2, i.e. 4a+b=-13)-2): 5a-5b=20, i.e. a+b=-4 so a=1, b=-5

then c = 6

Solution: 5x 2 6xy 2y 2 14x 8y 10 0 is arranged as: 5x 2 (6y 14) x 2y 2 8y 10 0 as the equation for x, then the discriminant of the root is equal to.

6y－14)^2－20(2y^2－8y＋10)＝－4(y＋1)^2

If there is a solution to the equation, then the discriminant equation " 0

So 4(y 1) 2> 0

Only y 1 when y 1 is solved, x 2 is solved

So the integer solution of the equation is x 2, y 1

Let's say there were x passengers at first, Y car.

then x=22y+1

x=k(y-1)，（k≤32）

The two forms are synonymous, and k is used to represent y: y=(k+1) (k-22)=23 (k-22)+1

Since y and k are both positive integers, k-22 is divisible by 23 so that k-22 = 1 or 23, giving k = 23 or 45 (rounded) so that y = 24 and x = 529