When k is an integer, the solution of the system of equations 2x + y = KX + 3Y = 6 is nonnegative?

When k is an integer, the solution of the system of equations 2x + y = KX + 3Y = 6 is nonnegative?

The solution of the system of equations is: x = 3K − 65y = 12 − K5, ∵ the solution of the system of equations is non negative ∵ 3K − 65 ≥ 012 − K5 ≥ 0, the solution is 2 ≤ K ≤ 12. ∵ K is an integer, ∵ k = 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

（x-2y）2n÷（2y-x）2n-1+（2x-y）（-2x-y）+（x-y）（-x+y）

The original formula = (2y-x) 2n ÷ (2y-x) 2N-1 + (y2-4x2) - (x2-2xy + Y2) = 2y-x + y2-4x2-x2 + 2xy-y2 = 2y-x-5x2-2xy

Derivative of function y = (x + 1) ^ 2 at x = 1
Such as the title

First, we reduce the degree of 2 times to y = x ^ 2 + 2x + 1. Then we get the derivative function as y '= 2x + 2. Finally, we substitute x = 1 to get the derivative function of Y at x = 1 as 4

I don't want all decimal addition and subtraction. I'll hand it in at the beginning of school!

1.45+15×6= 135 2.250÷5×8=400 3.6×5÷2×4=60 4.30×3+8=98 5.400÷4+20×5= 200 6.10+12÷3+20=34 7.(80÷20+80)÷4=21 8.70+(100-10×5)=120 9.360÷40= 9 10.40×20= 800 11.80-25= 55 12.70+45=115 13.90×...

General solution of differential equation (x ^ 2 + 1) y '+ 2XY cosx = 0
Method 1 total differentiation (I want to know what is total differentiation?)
The original equation can be changed into [(x ^ 2 + 1) * y] '= cosx (I don't understand this step) to seek the advice of an expert
We have two sides of X integral
（x^2+1）y=sinx+c
So the general solution of the original equation is:
y=(sinx+c)/(x^+1)

If DZ = & # 8706; Z / & # 8706; X DX + & # 8706; Z / & # 8706; y dy = 0, then the general solution U (x, y) = C
(x^2+1)y'+2xy-cosx=0
(x^2+1)dy+(2xy-cosx)dx=0
Or:
[(x^2+1)dy+(2xy)dx]-cosxdx=0
Because D (x ^ 2 + 1) y = (x ^ 2 + 1) dy + (2XY) DX
So: D (x ^ 2 + 1) y-dsinx = 0
The general solution is: (x ^ 2 + 1) y-sinx = C

Please explain the formula y = cos 2 α - 3cos α + 6 = 2cos & sup2; α - 3cos α + 5 = 2 (COS α - 3 / 4) & sup2; + 31 / 8 in detail

cos2α=cosαcosα-sinαsinα=cos²α-sin²α=2cos²α-1
y=2cos²α-1-3cosα+6=2cos²α-3cos+5
And then the recipe
=2(cos²α-3/2cosα+9/16)-9/8+5
=2(cosα-3/4)²+31/8

Put the nine numbers 1, 2, 3, 4, 5, 6, 7, 8, 9 in the box to make the equation hold. How many different ways can you think of? □□□=12×□□□=13×□□□

According to the stem analysis, 327 = 12 × 654 = 13 × 981, or 273 = 12 × 546 = 13819

Given the point a (1,1,1) in the space rectangular coordinate system o-xyz, the plane α passes through point a and is perpendicular to the straight line OA, and the moving point P (x, y, z) is any point in the plane α. (1) the conditions for finding the coordinates of point p; (2) the volume of the geometry enclosed by plane α and coordinate plane

(1) Because OA 8888\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\thearea of H is: 3 The volume of 0-mnh is 13 × 932 × 3 = 92

If the center of the ellipse is at the origin, taking the coordinate axis as the symmetry axis, and passing through two points P1 (6,1), P2 (− 3, − 2), then the elliptic equation is______ ．

Let the equation of ellipse be AX2 + BY2 = 1 (a > 0, b > 0, a ≠ b). Substituting two points P1 (6, 1), P2 (− 3, − 2) into the equation, 6a + B = 13A + 2B = 1, a = 19 & nbsp; b = 13, the elliptic equation is: X29 + Y23 = 1, so the answer is: X29 + Y23 = 1

If the product of two numbers is negative, can you tell us the symbols of the two numbers

According to the law of multiplication: if two numbers are multiplied, the same sign will get positive and the different sign will get negative, and the absolute value will be multiplied. If any number is multiplied by 0, it will get 0. According to the meaning of the question, the product of two numbers is negative, indicating that two numbers are different signs, that is, one positive and one negative