If 2lg (x-2y) = lgx + lgY, then XY=______ ．

If 2lg (x-2y) = lgx + lgY, then XY=______ ．

∵ 2lg (x-2y) = lgx + lgY, ∵ LG (x-2y) 2 = lgxy, ∵ (x-2y) 2 = XY, ∵ x2-5xy + 4y2 = 0, ∵ XY) 2-5 · XY + 4 = 0, ∵ xy = 1 (rounding off), or xy = 4, so the answer is 4

If 2lgx − y2 = lgx + lgY, find the value of XY

From 2lgx − y2 = lgx + lgY, we can get (x − Y2) 2 = xyx2 + y2-6xy = 0 (XY) 2 − 6xy + 1 = 0, and the solution is xy = 3 ± 22. From the definition domain of the function, we can know that XY > 1, so xy = 3 + 22, so xy = 2 + 1

If 2lg (x-2y) = lgx + lgY, then XY=______ ．

∵ 2lg (x-2y) = lgx + lgY, ∵ LG (x-2y) 2 = lgxy, ∵ (x-2y) 2 = XY, ∵ x2-5xy + 4y2 = 0, ∵ XY) 2-5 · XY + 4 = 0, ∵ xy = 1 (rounding off), or xy = 4, so the answer is 4

1 / 2, negative 3 / 4, 7 / 8, negative 15 / 16. The number 2010 in this series is, and the number n is?

Regardless of the sign denominator is 2,4,8,16 If {an} an = 2 * (1-2 ^ n) / (1-2) = 2 ^ (n + 1) - 2, then A2010 = 2 ^ 2011 - 2 molecules are 1,3,7,15 Is a second-order sequence of equal proportion, denoted as {BN} b2-b1 = 3-1 = 2b3-b2 = 7-3 = 4b4-b3 = 15-7 = 8

If the average of data x1, X2 and '''xn is 5 and the variance is 2, find the average of (3 X1 + 1), (3 x2 + 1) '' (3 xn + 1) and the variance
Help!

Put it in
These numbers can be 3,4,5,6,7 respectively. Then they are multiplied by three and one, and the result is 10,13,16,19,22
Then calculate for yourself
In fact, there is a rule:
A 1, a 2, a 3. An, mean n, variance M
If these data are multiplied by P and subtracted by Q, the new mean is pn-q and the variance is (P ^ 2) M

Given that the length of the diagonal of a square is l, find its perimeter and area

∵ in a square, the length of diagonal line = L, the length of side = the length of diagonal line △ 2 = 22L, the area of square s = the square of side length = 12l2, and the perimeter C = 4 × side length = 4 × 22 = 22

If y = x + 4 / x, X ＜ 0, find the maximum value of Y

Solution:
y=x+4/x
-y=-x-4/x=(-x)+(4/-x)
And because
x0
So - y = - x-4 / x = (- x) + (4 / - x) > = 4
Namely
-y>=4
So y

∫ x arcsinx DX integral

There is a large square. After cutting off a small square, the remaining side length is 9 and the area is 225 square centimeters. Find the area of the original large square

Let X be the minus side length,
(x+9)^2-x^2=225
We get x = 8
Original area = (8 + 9) ^ 2 =
Hey, hey, come on

A question in the Handbook of Chinese evaluation in the fifth grade of primary school
——Birds are the flowers of trees, and trees are the homes of birds. What a beautiful picture. There are many harmonious pictures in ancient poems. Please write a few

Li Shimin
Huipo moves to the central law, and ningxuan rises to Licheng. The clouds are covered, and the dew appears
Smile tree flower color, crow branch bird chorus
The bird sleeps in the tree by the pool, and the monk pushes the door under the moon
Several early warblers fight for warm trees, whose new swallow pecks the spring mud