A factory produces four-wheel drive toy cars at a cost of 16 yuan. At present, there are two ways to sell: the first way is to sell directly by the manufacturer's municipal department, and each car is sold in 20 yuan, which requires a fixed monthly fee of 1.520 yuan (including store sales rent, water and electricity, personnel salary, etc.). ); The second is wholesale.
Toy store sales, wholesale price 18 yuan per car, you should know that the tax paid by these two sales methods is 5% of sales.
(1) Find the functional relationship between the monthly profit y and the number of vehicles sold in the factory.
(2) If it is planned to sell 1500 in July,
Which sales method should be chosen for greater profit?
(3) For monthly sales
The number of vehicles, discuss what kind of sales.
Earn more profits?
(Analysis:
Every car
Expenditure expense
tax rate
expense
16 yuan
First kind
20 yuan
1520
5%
The second type
18 yuan
5%
)
( 1)
Profit = selling price-cost plus tax.
Then the first one: y=20x- 16x- 1520.
Type 2: y= 18x- 16x.
(2)
(Substitute 1500 into the above formula)
The first type: y = 20 *1500-16 *1500-1520 = 5480.
Type 2: y =18 *1500-16 *1500 = 3000.
So the first kind of profit is big.
(3)
First second = 20x-16x-1520-(18x-16x)
=2X- 1520
When 2x- 1520 >: 0 o'clock
X & gt760 hours
The first one is more than the second.
When 2x- 1520=0
That is, x=760.
The first is equal to the second.
When 2x- 1520
X < 760 hours.
The first one is smaller than the second one.
2. The straight line Y=2X-4 intersects the X axis and Y axis in A and B respectively.
At two o'clock, oh
Is the origin
( 1)
Find the coordinates of a and b;
(2)
Find the area of triangle AOB;
(3)
Can you draw a straight line through the vertex of the triangle AOB and divide the triangle AOB into two parts with the same area? If so, how many can you draw? Write the functional relationship corresponding to such a straight line.
2
(Intersecting with the X and Y axes is equivalent to X and Y being equal to 0.
Time)
( 1)
When a intersects the x axis, the ordinate of a is zero.
That is 0=2x-4.
So x=2.
When b intersects the x axis, the ordinate of a is zero.
That is, y=2*0-4.
So y=4.
So a (2,0)
B(0，4)
(2)
Because OA and OB are the x-axis and y-axis respectively.
So OA⊥OB
And OA=2.
OB=4
So s=2*4* 1/2=4.
(3)
Yes, when the straight line is the center line of a triangle.
The triangle it divides is a triangle with the same height and bottom.
So you can draw three lines.
The coordinates of this point are (1, 0) (0,2) (1,2).
So the equation is
y=2x
y=-x+2
y=-4x+4