How to calculate 243 * 15 * 2 with simple method

How to calculate 243 * 15 * 2 with simple method

243*15*2
=243*10*3=2430*3=7290

Let a and B be two points on the hyperbola x ^ 2 + y ^ 2 / 2, and point n (1,2) be the key point of line AB, then the equation of line AB is?

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The question is: "let A.B be two points on the hyperbola x ^ 2-y ^ 2 / 2 = 1, and point n (1,2) be the midpoint of the line AB, and find the equation of the line ab." if so, then
Let AB slope be K, a (x1, Y1), B (X2, Y2)
Then the linear AB equation is Y-2 = K (x-1)
We substitute it into hyperbolic equation, eliminate y, and sort it out
(2-k^2)x^2-2k(k-2)x+k^2-4k+2=0
Then X1 + x2 = 2K (K-2) / (2-k ^ 2)
Because point n (1,2) is the midpoint of line AB, that is X1 + x2 = 2
So 2K (K-2) / (2-k ^ 2) = 2
The solution is k = (1 ± √ 5) / 2

How to write 3x-4 * 6 = 18

3x-4*6=18
3x=18+24
3x=42
x=14

The image of function FX = x ^ 2aX + B passes through point (1,3), and for any real number x, there are f (- 1 + x) = f (- 1-x) functions y = FX and y = GX
Let FX = GX KFX be an increasing function on (- 1,1] to find the value range of real number K

1. F (x) has f (- 1 + x) = f (- 1-x) for any real number X. it shows that f (x) is symmetric relative to x = - 1, so f (x) = x & # 178; + 2x + B, passing through point (1,3), f (x) = x & # 178; + 2x; the image of G (x) and f (x) is symmetric about the origin, so g (x) = - f (- x) = - X & # 178; + 2x; 2

Simple calculation of 20.13 * 39 + 201.3 * 4.1 + 40 * 10.065

20.13*39+201.3*4.1+40*10.065
=20.13*39+20.13*41+20*20.13
=20.13*(39+41+20)
=20.13*100
=2013

Given that the distance from the point (x, y) to the origin is 2, find the maximum and minimum of x ^ 2 + XY-2

Change it for yuan
x²+y²=4
Let x = 2cos &;
y=2sin𝛉 𝛉∈(-π,π)
x²+xy-2=4sin²𝛉+4cos𝛉sin𝛉-2
=2(1-cos2𝛉)+2sin2𝛉-2
=2(cos2𝛉+sin2𝛉)=2√2sin(2𝛉+π/4)∈[-2√2,2√2]

When 99 is divided into 19 prime numbers, the maximum prime number is required to be as large as possible. Then, what is the maximum prime number?
beg

61
We need to make the others as small as possible, so try to make them 2 or 3
It can be 16 2's, two 3's and one 61's

What are the steps to expand the function of 3 ^ x into a power series of X?

f(x) = 3^x = e^(xln3) = ∑(xln3)^n/n! = ∑(ln3)^n*x^n/n!
-∞

Why is 2012 divided by 8.048 equal to 250

Dizzy, 8.048 is still interesting. Excuse me, 1 + 2 = 3. If 3 is interesting, 2 is interesting, then 3-2 =? Do you still ask why it is 1? Because 2012 is interesting and 250 is interesting, you can get 8.048 with 2012 / 250

It is known that there is at least one zero point of the function f (x) = ax ^ 2-3x + 1 on the right side of the origin, the value range of a, and the solution

According to the root formula: x = [- B ± √ (B & # 178; - 4ac)] / 2A:
(-3)(-3)-4a >= 0
The solution is a