I would like to thank you very much. Please list the equation, Fengrun department store has priced a pair of leather shoes at 165 yuan. If you sell them at 10% discount, you can still make a profit of 10%. What is the purchase price of leather shoes? In order to attract customers, all the goods are sold at 20% discount. It is known that the purchase price of a certain kind of tourist shoes is 60 yuan. After 20% discount, the profit margin is 40%. How much is the price of this kind of shoes? If a certain commodity is sold at a discount in the next season, it will lose 25 yuan if it is sold at a 25% discount, while it will earn 20 yuan if it is sold at a 10% discount. How much is the price of this commodity? The retail price of a certain commodity is 900 yuan per piece. In order to adapt to the market competition, the store decided to reduce the price by 10% of the selling price and sell it at a profit of 48 yuan, still 20% vitality. How much is the purchase price of this product?

What about the question?
1. The purchase price is x yuan
165*90%=x(1+10%)
x=135
2. The price is x yuan
80%x=60(1+40%)
x=105
3. The price is x yuan
75%x=(90%x-20)-25
x=300
4. The purchase price is x yuan
900*90%-48=x（1+20%)
x=635
Simple enough ~ ha ha

If the solution of the equation 3-2 (X-5) = 21 and 3 / ax-7 = 1 about X are the same, what is the value of a

If the solution of the equation 3-2 (X-5) = 21 and 3 / ax-7 = 1 about X are the same, what is the value of a
3-2 (X-5) = 21
2（x-5）=-18
x-5=-9
x=-4
ax-7=-3
-4a-7=-3
-4a=4
a=-1

What is the value of a if the solution of noel's equation 3-2 (X-5) = 21 is the same as that of ax-7 = - 1?

3-2 (X-5) = 21 3-2x + 10 = 21 2x = - 8, x = - 4 is substituted into the second equation, (- 4a-7) / 3 = - 1 - 4a-7 = - 3 4A = - 4 a = - 1

”Simple calculation of "five minus five times two fifths plus three fifths"

Equal to five minus five times (two fifths plus three fifths)
It's five minus five times one
It's five minus five
It's zero

Why is the form of transforming 2x & # 178; + 4x into a (x + H) &# 178; + K (where a, h, K are constant terms) 2 (x + 1) &# 178; - 3
(2a + 3b) & #178; = (2a-3b) & #178; + () why 24ab

2x²+4x=2(x²+2x+1)-2=2(x+1)²-2;
（2a+3b）²=(2a-3b)²+（）
4a²+9b²+12ab=4a²+9b²-12ab+();
()=12ab+12ab=24ab;

What is 720000 divided by 8000

90
Subtract three zeros from both sides at the same time
Become 720 / 8 = 90

Find the minimum value of 3 times x square + 6x + 5 / 1 / 2 times x square + X + 1

(3x^2+6x+5)/(x^2/2+x+1)
=(6x^2+12x+10)/(x^2+2x+2)
=[6(x^2+2x+2)-2]/(x^2+2x+2)
=6-2/(x^2+2x+2)
=6-2/[(x+1)^2+1]
(x+1)^2≥0 (x+1)^2+1≥1
0

(1 and 5 out of 11 plus 8 out of 13 plus 6 out of 17) divided by (8 out of 11 plus 4 out of 13 plus 3 out of 17)

（1 5/11+8/13+6/17）/（8/11+4/13+3/17）
=（16/11+8/13+6/17）/（8/11+4/13+3/17）
=16/11/8/11+8/13/4/13+6/17/3/17
=2+2+2
=6

An algorithm for multiplication of polynomials of one variable
RTRT
Be sure to talk about it first
If there is a better program, you can do without it
But it has to be told

A structure can be defined, in which there are three variables, one is coefficient, one is index, and one is pointer to the next term. A polynomial is represented by a linked list structure. When two polynomials are multiplied (assuming the first is m term and the second is n term), as long as the coefficient of each term of the first polynomial is multiplied by the second polynomial

Using 95% and 70% alcohol solution to prepare 1 kg of 75% disinfectant alcohol, how many grams of each alcohol are needed?

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I drink Coca Cola in the desert, sing karaoke, ride a lion, drive ants, and answer questions for you with a keyboard in my hand!