1,9,19,29,39, regular

1,9,19,29,39, regular

49 59 69

If 2x-5y + 2 = 0, try to find the value of 4 ^ x * 1 / 32 ^ y

Because 2x-5y + 2 = 0
So 2x-5y = - 2
4^x*1/32^y
=2^2x/2^5y
=2^(2x-5y)
=2^(-2)
=1/4

According to 7 / 5 minus 1 / 2, an addition formula is {} A. 5 / 7 plus 3 / 14 equals 1 / 2 b. 1 / 2 plus 3 / 14 equals 5 / 7 C
One in two plus seven in five is three in fourteen

B. One in two plus three in fourteen is five in seven

Let f (x) = Xe ^ KX (k is not equal to 0)
(1) Find the tangent equation of the curve y = f (x) at the point (0, f (0));
(2) Find the monotone interval of function f (x);
(3) If the function f (x) increases monotonically in the interval (- 1,1), the value range of K is obtained
I know the answer to the third question is [- 1,0) U (0,1]. I hope you can give me the correct process of solving the third question,

First, the derivative expression of F (x) is obtained as f '(x) = (1 + XK) e ^ KX
When x = 0, the derivative is 1, so the tangent equation is y = X
2. Monotone interval, that is, f '(x) > = 0 is monotone increasing, f' (x) = 0 is monotone increasing, (1 + XK) 0: x > = - 1 / K, f (x) is monotone increasing, XK > = - 1
So the value range of K is [- 1.0) and [1, infinity]

What is the quotient of the sum of 2 and 1 / 2 and its reciprocal divided by 1.25 and 4 / 5?
This is a column calculation

（2.5+0.4）÷（1.25X0.8）
=2.9÷1
=2.9

Please write the number of polynomials with degree 2, number of terms 3 and constant term negative one

X×X+2X-1=0

The difference and relation between integrand function and integrand expression
If you can, please give me an example. I feel dizzy

The integrand expression includes the integrand function. The integrand function has a wide range

Given M-N = 4 m square + n square = 10, find the value of Mn square - m square N and 2m + 2n
Given M-N = 4 m square + n square = 10, find the value of Mn square - m square N and 2m + 2n

(m-n)^2=16
m^2-2mn+n^2=16
Because: m ^ 2 + n ^ 2 = 10
So: - 2Mn = 6
mn=-3
Because: M-N = 4
m=4-n
So: (4 + n) n = - 3
N = - 1 or n = - 3
Because: M-N = 4
So: M = 3, n = - 1

What's the quotient of subtracting the product of 5 / 4 and 2 / 3 from 2 and dividing it by 7 / 9

（2-5/4*2/3）/（7/9）=7/6*9/7=3/2

How to judge whether a matrix is invertible if it is 1002k4
How to judge whether a matrix is invertible
If the matrix is 1 0
2 k 4
5 -6 3
This matrix is not invertible, so what is k equal to

First of all, it is clear that the invertible matrix must be a square matrix, and the simple criterion is that the determinant is not zero