There are some of the same rooms that need to be painted, and 3 masters go to paint 8 rooms a day

The area of each room is a, the master completes x in one day, and the apprentice completes y in one day, as can be seen from the question: y=x-30.

First question:

Equation 1: 8a = 3x+40

Equation 2: 9a=5y=5(x-30) gets:a=50;x=120；y=90

Second question (takes z days):

1*z*120+2*z*90=36*50 gets: z=6.

The third question (employing m masters, n apprentices, and the salary is b):

Equation 1: m*3*120+n*3*90=36*50=1800 i.e.: 4m+3n=20

Get: n=(20-4m) 3

Equation 2: 3*85*m+3*65*n=b Bring n in: b=1300-5m

From "b=1300-5m", it can be seen that only when m is the largest, b is the smallest, so all 3 masters are required. Bring in n=(20-4m) 3 to get n=8 3, round n=3

3 masters are all hired, and 3 apprentices are hired.

There are some of the same rooms that need to be painted, and 3 first-class technicians go to paint 8 rooms a day, and the result is that 50 square meters of the walls have to be painted in the future.

1 Let the first-level mechanic paint the area of x in one day, and the second-level area is y, and the area of a wall is set to the system of equations in column A 3x=8a-50

5y=10a+40

x=y+10

Solve the system of equations x=122

y=112a=52 The answer is 52 square meters.

Solution: You got it right in the first and second questions!

1) Set the wall of each room is x square meters.

According to the problem, list the equation: (8x-40) 3-30=(9x) 5 solution x=50

A: The wall area of each room is 50 square meters.

2) It takes Y days to complete.

According to the question, list the equation: y=36 50

Solution: y=6Answer: It takes 6 days to complete.

3) First find out the total area of the wall: 36 50 = 1800 square meters, set up M masters, N apprentices, and the salary is A yuan:

Equation 1: m 3 120 + n 3 90 = 1800, that is: 4m + 3n = 20

Solution: n=(20-4m) 3

Equation 2: 3 85 m+3 65 n=a

Bringing n into Eq. 2 yields: a=1300-5m

From a=1300-5m, it can be seen that only when m is the largest, a is the smallest, so all 3 masters must be hired.

Bring m=3 into n=(20-4m)3

The solution is n=8 3, and the integer solution is taken: n=3

Answer: 3 masters are all hired, and 3 apprentices are hired.

I wish you progress in your studies!!

(1) Set the area of the wall that needs to be painted in each room as x m2 as the title suggests, 8x-40 3

9x 530, solution: x=50

Answer: Set the wall area that needs to be painted in each room is 50m2 (2) by (1) set the wall area that each master paints every day is 8 50-40 3 = 120 m2, and the wall area that each apprentice paints every day is 120-30 = 90 m2, and it takes 50 36 (120 + 180) = 6 days for 1 master to paint 36 rooms with two apprentices

A: If you ask 1 master to bring 2 apprentices, it will take 6 days to complete

Solution: Set each room xm2.

Each master has a daily feast (8x-40) 3

Each apprentice imitates the auspicious judgment brother and brushes 9x 5 per day

Equivalence relation: the master brushes the wall every day - the apprentice paints every day = 30m2.

So we can list the equation: (8x-40) 3-9x 5=30 to solve x=50

Then 50 m2 per wall.

I don't know how many walls there are. 5。。。sorry，i don‘t know...

I can't solve it! You didn't say how many rooms had to be painted.

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Set up, the master paints x square meters a day, and the apprentice paints x 30 square meters a day.

3 masters paint 3x square meters a day, and 5 apprentices paint 5 (x-30) square meters.

Column equations. (3x 40) 8 5(x 30) 9 solution. x 120 (square meter days).

x 30 90 (square meter days).

1. (120 3 + 40) 8 50 (square meters) 2. 36 rooms need to be painted: 50 36 1800 (square meters) 1800 (120 + 90 2) 6 (days).

3. The master's daily salary is 85 yuan, painting 120 square meters, and the unit price per square meter: 85 120 17 24

The apprentice's daily salary is 65 yuan, painting 90 square meters, and the unit price per square meter: 65 90 13 18

13 18 is greater than 17 24, so it is more cost-effective to ask for a master than to invite an apprentice.

And the 3 masters can only paint in 3 days: 120 3 3 1080 (square meters) and 720 square meters need to be used apprentices: 720 90 8 (person-times) ......3 days per person, 3 people 9 days, 1 person only needs to be hired for 2 days.

Therefore, it is most cost-effective to hire 3 masters for 3 days, 2 apprentices for 3 days, and 1 apprentice for 2 days.

(1) Find the wall area that needs to be painted in each room;

30*3-40=50 (square meters).

2) Boss Zhang has 36 such rooms that need to be painted, if you ask 1 master to take 2 apprentices, how many days will it take to complete?

A master brushes a day: (50*8-40) 3=120 (square meters) An apprentice brushes a day: (50*9) 5=90 (square meters) = 6 (days) (3) It is known that each master, the daily salary of the apprentice is 85 yuan, 65 yuan, Boss Zhang requires it to be completed within 3 days, and asks how to hire people among these 8 people, is it cost-effective?

Average completion per day: 36*500 3

600 (sqm).

Two masters are hired and four apprentices are the most suitable.

Solution: Set the room area to YM2, and the master paints XM2 a day

3x=8y-40

x-30）*5=9y

The solution is x=120 y=50

1) The wall area that needs to be painted in each room is 50m2;

2) 50*36 (120+90*2)=6 days.

3) Among the 8 people, 2 masters and 4 apprentices are arranged, which is the most cost-effective.

(1) The area of the wall that needs to be painted in each room is x, (8x-40) 3-9x 5=30---x=50

2) There is the first question to know that the master can brush (8*50-40) 3=120, and the apprentice 90So the answer is 36*50 (120+90*2)=6

Your topic is not complete yet, I will fill you in completely:

1) Find the area of the wall in each room (I calculated that it is 52 square meters).

2) Zhang Laofu has 36 such rooms that need to be painted, if you ask 1 master to take 2 apprentices, how many days will it take to complete? (I calculated it was 6 days).

3) It is known that the daily wages of each master and apprentice are 85 yuan and 65 yuan respectively, and Boss Zhang requires it to be completed within 3 days, and asks how to hire people among these 8 people, so that it is cost-effective?

Answer: The area of each room is A, the master completes x in one day, and the apprentice completes y in one day, as can be seen from the question: Lap limb y=x-30.

First question:

Equation 1: State A: 8a=3x+40

Equation 2: 9a=5y=5(x-30) gets:a=50;x=120；y=90

Second question (takes z days):

1*z*120+2*z*90=36*50 gets: z=6.

The third question (employing m masters, n apprentices, and the salary is b):

Equation 1: m*3*120+n*3*90=36*50=1800 i.e.: 4m+3n=20

Get: n=(20-4m) 3

Equation 2: 3*85*m+3*65*n=b Put n with wheels into the world: b=1300-5m

From "b=1300-5m", it can be seen that only when m is the largest, b is the smallest, so all 3 masters are required. Bring in n=(20-4m) 3 to get n=8 3, round n=3

3 masters are all hired, and 3 apprentices are hired.

The area of each room is a, the master completes x in one day, and the apprentice completes y in one day, as can be seen from the question: y=x-30.

First question:

Equation 1: 8a = 3x+40

Equation 2: 9a=5y=5(x-30) gets:a=50;x=120；y=90

Second question (takes z days):

1*z*120+2*z*90=36*50 gets: z=6.

The third question (employing m masters, n apprentices, and the salary is b):

Equation 1: m*3*120+n*3*90=36*50=1800 i.e.: 4m+3n=20

Get: n=(20-4m) 3

Equation 2: 3*85*m+3*65*n=b Bring n in: b=1300-5m

From "b=1300-5m", it can be seen that only when m is the largest, b is the smallest, so all 3 masters are required. Bring in n=(20-4m) 3 to get n=8 3, round n=3

3 masters are all hired, and 3 apprentices are hired.

It is known that the daily wages of each master and apprentice are 85 yuan and 65 yuan respectively, and Boss Zhang requires it to be completed within 3 days, and asks how to hire people among these 8 people before accounting? (Please ask the teachers to answer, there are many, many kinds of oh, to the equation) you know.

How big is the room? The difference between the master and the apprentice is the technology or the speed, and the area of the owner is counted as a door or window when the owner paints.

Set up a second-level technician to brush x square meters every day.

5x-40)/10=(3(x+10)+50)/8x=112

5x-40)/10=52

Therefore, each room needs to be painted 52 square meters.