Middle School Mathematics Help with the answer Thank you 6 7 questions

I calculated that the value of a is 50, but substituting 8 3a is not enough.

(1) Set the ** of each box of red Fuji to be x yuan; The ** of ivory mango is (2x-10) yuan.

400x*3/8+400(2x-10)*5/8=22000+80003x/8+10x/8-50/8=75

13x=75*8+50=650

x=502x-10=90

Each box of "ivory mang" sells for at least 90 yuan. （2）

Class A: 183 Class B: 70*3*If less than 30 bottles are purchased in 2 days, less than 70 bottles; If you buy more than 50 bottles in 2 days, it will exceed 70 bottles; If you buy 30-50 bottles on both days, the total price is 70*3*, which is less than the 183 mentioned in the question, so it is concluded that the purchase quantity is less than 30 bottles on the first day, and the purchase volume is in the range of 30-50 on the second day.

Suppose you buy x bottles on the first day, then buy (70-x) bottles on the second day, and you get the equation: 3x+3* 25 bottles on the first day and 45 bottles on the second day.

Set: The number of machines originally planned to produce A in the first quarter is x; The number of machines originating B in the second quarter was y; x+y=480x(1+10%)+y(1+20%)=554, and you should be able to solve the rest.

1) Class B pays 33 yuan less than Class A.

2) The second question went wrong.

Let the original price of radish x and the original price of pork ribs y, then, the current price of radish x (1 + 50%) =, the current price of pork ribs y (1 + 20%) =, the total price of the previous month: 3x + 2y = 36 ......Equation 1

Total price for this month: 3 * Equation 2

Equation simultaneous solving: x=2, y=15

Then, radish yuan, pork ribs are now priced yuan,

Let the original price of radish be x the current price. The original price of pork ribs is y, the current price.

3x+2y=36 3x multiplication.

The solution is x=2 y=15

Solution: Let the large number be x and the small number y

x+y=68

100x+y)-(100y+x)=2178 Equation 2) Finishing: x-y=22

1)+3) 2x=90 x=45x=45 substitution into 1) y=68-45=23 x=45 ; y=23

Answer: The large number is 45 and the decimal number is 23

Let these two two-digit numbers be x (larger) and y respectively, and x+y=68 from the title

100x+y)- 100y+x)=2178 to solve this system of equations.

Let these two numbers be x and y

x+y=68

100x+y-100y-x=2178

The solution is x=45 y=23

If the larger two-digit number is ab, then ab10-10ab = 2178ab10 10ab

ab=32, so the two two-digit numbers are 32 and 36

One is that the exponent is 0 and the base is greater than 0

One is that the base number is 1 and the exponent is arbitrary.