The key to math questions is question 2! Ask a math question!

1) Solution: Set up a car with 45 seats to rent x cars.

45x=60(x-1)-30

45x=60x-60-30

15x=90

x=645*6=270 (person).

A: Rent 6 cars with 45 seats, a total of 270 people.

There are 6 cases in total.

5 large and 0 small: 300 * 5 = 1500 (yuan).

4 large and 1 small: 300 * 4 + 250 = 1450 (yuan) 3 large and 2 small: 300 * 3 + 250 * 2 = 1400 (yuan) 2 large and 4 small:

300 * 2 + 250 * 4 = 1600 (yuan) 1 large 5 small: 300 + 250 * 5 = 1550 (yuan) 0 large 6 small: 250 * 6 = 1500 (yuan).

It can be seen that 3 cars with 60 seats and 2 cars with 45 seats are the most cost-effective.

1. (1) Solution: You can take X car.

45x=60（x-1）-30

45x=60x-60-30

45x=60x-90

90=60x-45x

90=15x

x=6 2)6x45=270 (person).

A: There were 270 people on the trip. Rent 6 cars with 45 seats.

2. (1) 250x6=1500 (yuan).

2) Because 270 = 60 + 60 + 60 + 45 + 45, 3 cars for 60 seats and 2 cars for 45 seats are rented.

A x B y

x=y/x=2/3

The number B is 2 3 times the number A.

x/y=3/2

The simplest integer ratio of numbers A and B is 3 2

The number B is 2/3 of the number A, and A:B = 3:2

50*25*cubic meters) A: 1500 cubic meters are required.

cubic decimeter) 22500 (ml).

22500 750 30 (bottles) A: It can hold 30 bottles.

Cubic metre. , 750ml = 750 cubic centimeters, 25x25x36 = 22500, 22500 750 = 30 (bottle).

1) Simple volume problem: length * width * height: 50 * 25 * (cubic meters).

2) The volume of oil in the oil drum can be divided by the volume of the oil bottle to obtain the number of bottles that can be filled (the unit should be unified, what meter is dm) (bottle).

1) cubic meters.

2) cubic decimeters.

750ml = cubic decimeter.

In addition to being able to hold 30 bottles.

50*25*

bottle) -- the unit is not a milliliter——!

1. How much yuan did Wang Le spend on buying a pair of badminton rackets? 39*

How much cheaper than the original? 39*（

Li Dong bought a basketball and a pair of table tennis rackets, how much yuan did they share? How much cheaper than the original?

2. How much is the original price of this radio?

Find the maximum value of the function on [1/2,2] is x=2,y=approximately.

and the minimum value x = , y = about -1 60

Through the first question, the function f(x)=-x 2 3+2x-4lnx 3 is derived, and after the derivative f(x)=-2x 3+2-4 3x, the quadratic derivative f(x)=-2, 3+4, 3x 2, and the extreme value is obtained, i.e., f(x)=0, and x=root number 2 is solved

Because 1 2 root number 2 2

Therefore, 1 2, root number 2, and 2 are substituted into the original function to compare the size to determine the maximum value.

When n tends to infinity, the larger the denominator, the smaller the fraction, so that the nth power of (1 2) is equal to zero. Finally, the result is calculated.