Can 998 ^ 2-899 * 879-1 be divisible by 100? Please explain with the knowledge of factorization

Let t = 100,
Original formula 998 ^ 2-899 * 879-1
=(10t-2)²-(9t-1)(9t-21)-1
=19t²+158t-18
=t(19t+158)-18
=205800-18
So it's not divisible by 100

Can 998 ^ 2-899 * 897-1 be divided by 100? Please explain the reason with the knowledge of factorization

998^2-899*897-1
=998^2-(898+1)*(898-1)-1
=998^2-898^2+1-1
=998^2-898^2
=(998+898)*(998-898)
=(998+898)*100
So it's divisible by 100

As shown in the figure, the quadrilateral ABCD is a rectangular land, ab = 3, BC = 1, and points e, F, G and H are on AB, BC, CD and Da respectively,
Let EB = BF = GD = DH = x, then what is the maximum area of efgh in the newly-built quadrilateral garden

S=3*1-0.5x^2-0.5x^2-0.5(1-x)^2-0.5(1-x)^2
S=3-x^2-(1-x)^2
S=-2x^2+2x+2
S=2(-x^2+x+1)
When x = 0.5, s has a maximum
The maximum s is 2.5

The school bought 50 pencils and 10 pens with 120 yuan. The price of a pencil is one seventh of that of a pen. What are the unit prices of pencils and pens
Do it by formula

First of all, suppose the pencil is x yuan, then the pen is 7x yuan. A pen = 7 pencils. 50 pencils + 7 * 10 pencils = 120 yuan. 50x + 10 × 7 (x) = 120 (50 + 70) x = 120. 120x = 120 x = 120. Thus, a pencil is 1 yuan, and a pen is 7 yuan

Xiaowen and three students take a taxi to visit the Museum 5 kilometers away from the school. They know that they have to pay 6 yuan for the first 2 kilometers, and they will pay 1 kilometer more for the next,
The fare is 1.6 yuan. How much is the average fare per person when they arrive at the museum?

[6 + (5-2) * 1.6] / 4 = 2.7 yuan
I wish you progress in your study!

The top and bottom of a cuboid are rectangles, the length and width of which are 5cm and 4cm respectively. The front and back faces of the cuboid are square. The surface area of the cuboid is () cm at most

Upper and lower 5 * 4 * 2 = 40
5 * 5 * 2 = 50 or 4 * 4 * 2 = 32
If it is 5 * 5, the left and right sides are 4 * 5 * 2 = 40, and the surface area is 40 + 50 + 40 = 130
If it is 4 * 4, the left and right sides are still 4 * 5 * 2 = 40, and the surface area is 40 + 32 + 40 = 112
So it's 130 at most

The freight cars and passenger cars set out from two places 210 kilometers apart at the same time and travel in opposite directions. When they meet, the passenger cars travel two fifths more than the freight cars. How many freight cars do they travel when they meet
Connect ↑ km?

Freight car line 210 (1 + 1 + 2 / 5) = 210 / 12 / 5 = 87.5km

Mathematics in life: practical problems? Fast
XX asked his mother for some pocket money. During the activity, XX bought small gifts with 2 / 3 of his pocket money and food with the remaining 2 / 3. When he got home, he found that it was only 4 yuan. How much did XX want
To be detailed!!!!!!!!

Backward push
Before buying food, there are:
4 ÷ (1-2 / 3) = 12 yuan
It turns out that:
12 (1-2 / 3) = 36 yuan
Comprehensive formula: 4 ÷ (1-2 / 3) ÷ (1-2 / 3) = 36 yuan

Use a 62.8 decimeter long wire to form a square. How much is the square? If it is a circle, what is the area of the circle
It's going to be tonight!!!!

Perimeter of square = 62.8 decimeters
Side length of square = 62.8 △ 4 = 15.7 decimeters
Square area = 15.7 × 15.7 = 246.49 square decimeters
Circumference of circle = 62.8 decimeters
Radius of circle = 62.8 △ 2 △ 3.14 = 10 decimeters
Area of circle = 3.14 × 10 & # 178; = 314 square decimeters

Can 998 ^ 2-899 * 879-1 be divisible by 100? Please explain with the knowledge of factorization