Math problems need to be processed, fast, urgent, and math problems are fast to process

1) Let the calculated ellipse c equation be x 2 a 2 + y 2 b = 1.

As can be seen from the title, a=4, c=3.

So, b 2 = a 2 - c 2 = 7.

The equation for the ellipse c is: x 2 16 + y 2 7 = 1.

2) The eccentricity of the ellipse c is c a=3 4, and the right alignment equation is x=a 2 c=16 3.

Let p(x0,y0), then the distance from point p to the right alignment is d=16 3-x0.

From the geometric properties of the ellipse, it can be obtained: |pf|d=3 4, i.e. d=(4 3)|pf|。

So, |pa|+(4/3)|pf|=|pa|+d。

Make the right alignment of the AH vertical ellipse C, and the perpendicular foot is H.

Let the line segment ah intersect the ellipse at the point p0.

When the point p is the point p0, |pa|+(4/3)|pf|=|pa|+d=|ah|=16/3-(-1)=19/3。

Conic curves... Forgot to clean it. Help you top it.

1: Open squared, x minus two equals plus or minus seven, so x is equal to nine or minus five, 2: open squared, 3x minus one equals plus or minus five. So 3x is equal to six or minus four, so x is equal to two or minus four-thirds.

3: For this equation to be meaningful, so three minus three a should be greater than or equal to 0, and solve the equation so that a is less than or equal to one.

The landlord looks at the hard work of typing!

or -7 then x=9 or x=-5 or -5 then x=2 or x=-4 3 3It can be seen that 3-3a is greater than or equal to 0, then a is less than or equal to 1

(x-2)^2=49

x-2 = plus or minus 7

So x1 = 9 or x2 = -5

3x-1)^2=25

3x-1 = plus or minus 5

3x = 6 or -4

x1 = 2 or x2 = -3 4

3-3a>=0 -3a>=-3 a<=1

1. Solution: x-2 = (root number) 49

x-2=7x=92, solution: 3x-1=5

3x=6x=23, the number in the root number must be greater than or equal to 0

3-3a≥0

3≥3aa≤1

Solution: Let the average velocity from A to B be x h, then the average velocity from B to A is (x+4)km h

A: ......

Let the velocity from A to B be x (in km h), then the velocity from B to A is 40 + the distance from xa to B: 36x 60=

Distance from B to A: 30(x+40) 60=

Then there is: x=200, that is, the speed of the train from A to B is 200km h(1): if you set a type x lamp, then type b has 50-x lamp.

There is 40x+65(50-x)=2500

x = 30, i.e. 30 lamps for type A and 20 lamps for type B.

2): by the title.

Type A is priced at 60*, while Type B is priced at 100*

The profit of each lamp of type A is 54-40=14, then the profit of type B is 80-65=15 The profit of all sold out is: 14 * 30 + 15 * 20 = 720 (yuan).