How to decompose the fourth power of X - the second power of 8x - 16 emergency

How to decompose the fourth power of X - the second power of 8x - 16 emergency

x^4-8x^2-16
=x^4-8x^2+16-32
=(x^2-4）^2-32
=(x^2-4）^2- （4√2）^2
=(x^2-4-4√2)(x^2-4+4√2)

Calculate: (X-5) (x-3) + 1. Is the final result the square of x-8x + 16 or the square of (x-4)
Which one should I fill in when I write the blanks?

Of course, it's the square of X - 8x + 16 ~ it's the simplest way to score

Proof of LIM {the square of 4x divided by (the square of x minus 4)} = 4

The numerator denominator is the square of X
LIM (4 / (the square of 1-4 / x))
X - > infinity, square of 4 / x = 0
Original formula = 4 / 1 = 4

A square is divided into three rectangles, one of which has a perimeter of 16 meters. What is the area of the original square?
It's going to be formulaic!

36 square meters
16 / 2 = 8 (length width sum of rectangle)
8 / (3 + 1) = 2 (the square is divided into three rectangles with the aspect ratio of 3:1)
2x3 = 6 (a square is the length of a rectangle)
6X6=36

Simplify the 101 power of negative 2 + 102 power of negative 2=

101 102 101 101 1
（－2） ＋（－2） ＝ －2 ＋ 2 ×2
101 101
＝ 2 （－1＋2）＝ 2

It takes 21 seconds for a train to pass a 120 meter long bridge and 17 seconds to pass an 80 meter long tunnel. How long is the train

When a train passes through a bridge or tunnel, it means that it enters from the front of the train and leaves from the rear of the train. Then the distance of the train is the length of the bridge or tunnel plus the length of the train. The train is x meters long and runs at a constant speed
(x+120)÷21=(x+80)÷17
17×(x+120)=21×(x+80)
X = 90 meters. That is, the length of the train is 90 meters

After a round piece of paper is cut, it is put together into an approximate rectangle with the width equal to the radius and the area unchanged. The perimeter of the rectangle is 33.12 cm. Calculate the area of the round paper

Circumference of rectangle = circumference of circle + 2 × radius
2 × 3.14 × radius + 2 × radius = 33.12
28 radius = 33.12
Radius = 4 cm
Area = 3.14 × 4 & # 178; = 50.24 square centimeter

Number than size, 3 to the 55th power and 4 to the 44th power how to compare size, urgent

The 55th power of 3 = the 11th power of the 5th power of 3
The 44th power of 4 = the 11th power of the 4th power of 4
The fifth power of 3 = 243
The fourth power of 4 = 256
So the fifth power of 3 is less than the fourth power of 4
therefore
The 55th power of 3 is less than the 44th power of 4

The taxi charge standard of our city is shown in the table below: 8 yuan for more than 3000 meters, 2 yuan for each additional kilometer for more than 3 kilometers and 3 yuan for each additional kilometer for more than 8 kilometers
Xiao Ming is going to take a taxi. The distance is 7 kilometers. Please calculate the minimum cost

8 + (7-3) * 2 = 16 (yuan)
A: it costs at least 16 yuan to travel 7 kilometers

As shown in the figure, in trapezoidal ABCD, ab ‖ CD, m and N are the midpoint of CD and ab respectively, and Mn ⊥ ab. trapezoidal ABCD must be isosceles. Please explain the reason in two different ways

Method 1: connecting am and BM, ∵ n is the midpoint of AB, ∵ an = BN, and ∵ Mn ⊥ AB, ∵ am = BM, ∵ amn = ∠ BMN, ∵ m is the midpoint of CD, ∵ cm = DM, and ∵ am = BM,