Then it is 5 * (1+a) (1+a) = 8.45.
A=0.3 or a=-2.3 (truncated)
2) a=0.3 from 1)
20 1 1 year, with an investment of 5 *1.3 = 650 million yuan.
The total investment in three years is 5+6.5+8.45 = 65.438+99.5 million yuan.
2. If the price rises by X yuan per kilogram, the daily sales will drop by 20 kilograms.
Then the daily profit is (10+x)*(500-20x)=6000.
Solvable x=5 or x= 10.
It also requires customers to get the maximum benefit, so x= 10 gives up.
5 yuan per kilogram.
3, 1) As can be seen from the above table, whenever x increases 1 yuan, y corresponds to +2 blocks.
So y=20+2x
2) If the price is reduced by x, the daily pressure will be (40-x)*(2x+20)= 1200.
Solvable x= 10 or x=20.
X= 10 (omitted) because it wants to attract the most customers.
Therefore, if the shopping mall sells these clothes, it should not only ensure the daily profit of 1200 yuan, but also attract more customers, and each dress should be reduced by 20 yuan.
3) let the daily profit be t.
Then t=(40-x)*(2x+20)
=-2x^2-20x+80x+800
=-2x^2+60x+800
=-2(x^2-30x)+800
=-2(x- 15)^2+ 1250
Because (x- 15) 2 >: =0.
Sulfur dioxide (x- 15) 2
So t < = 1250
Therefore, the daily profit of this batch of clothes sold in shopping malls cannot reach 1300 yuan.