Seven out of eleven times four out of thirteen plus nine out of eleven times seven out of thirteen

Seven out of eleven times four out of thirteen plus nine out of eleven times seven out of thirteen

7/11×4/13+9/11×7/13=7/13×4/11+9/11×7/13=7/13（4/11+9/11）=7/13×（13/11）=7/11

How much is seven out of nine divided by eleven out of five plus two out of nine multiplied by five out of eleven

7 / 9 divided by 1 / 5 11 plus 2 / 9 multiplied by 5 / 11 = 7 / 9 * 5 / 11 + 2 / 9 * 5 / 11
=（7/9 + 2/9 ） * 5/11
=5/11

Zero is a natural number and the smallest natural number is zero, right? Is there any rational number? Can rational numbers be divided into positive and negative numbers? Is 3:25 a decimal? Is wood rational?

Zero is a natural number and the smallest natural number is a pair of zeros
It's not irrational
Rational number can be divided into positive number and negative number, wrong, and 0
3:25 is a decimal, not a rational number. No, it's a rational number

How to build a middle school library into a second classroom for teachers and students

Abstract: the construction of the secondary school library into the second classroom enriches the students' after-school life, gives full play to the role of the school library, and also improves the overall quality of teachers and students

It is known that f (x) is differentiable at x = 1, and the derivative of F (1) is 3. Find the value of LIM [f (1 + H) - f (1)] / h when h tends to 0
Know the answer is 3, can you give me a reason, I'm stupid

f'(1)=3
∴lim[h→0] [f(1+h)-f(1)]/h=3
This is the definition of derivative
Derivative definition
f'(x)=lim[h→0] [f(x+h)-f(x)]/h
And f '(a) = Lim [h → 0] [f (a + H) - f (a)] / h

It is known that the function f (x) is an even function defined on R, and if x is less than or equal to 0, f (x) = - x + X, find the expression of F (x) and draw the graph of F (x)

f(x)=x^2-x
If you draw a picture, it is a parabola with the vertex at (1 / 2, - 1 / 4)
The intermediate formula of transformation is f (x) = (x-1 / 2) ^ 2-1 / 4
If the even function is defined like this, f (x) = f (- x)

English translation
What kind of color or sound do you like~

Would you like this kind of something?
What kind of something would you like?

How high is 4-9? How high is 5-8?

1 inch = 0.0254 meters 1 foot = 0.3048 meters 4 feet 9 inches = 1.45 meters 5 feet 8 inches = 1.72 meters

When t tends to zero, LIM (Sint + cost-1) / T = LIM (cost Sint) = 1)
Why LIM (Sint + cost-1) / T = LIM (cost Sint) = 1 when t tends to 0)

This is a differential equation. The derivative of sin t is cost, the derivative of cost is - Sin T, the derivative of - 1 is 0, and the derivative of T is 1

Sorry to disturb you

Excuse me,I am sorry for bothering.