If one side of the rectangle is x and the area is y, y is expressed as a function of X

If one side of the rectangle is x and the area is y, y is expressed as a function of X

The length of the other side is
√(50^2-x^2)=√(2500-x^2)
y = x√(2500-x^2)（0

A box of biscuits is 20cm in length, 15cm in width and 30cm in height. It needs to be pasted with brand paper around it. How many square centimeters is the area of this brand paper at least?

(30 × 15 + 20 × 30) × 2, = (450 + 600) × 2, = 1050 × 2, = 2100 (square centimeter); answer: the area of this brand paper is at least 2100 square centimeter

The cuboid box is 10cm long, 6cm wide and 15cm high. Label around the box. How many square centimeters is the area of the label

The key to solve the problem: 1. Which side is the trademark (front, back, left, right)
2. How to calculate the area of these four surfaces
(10 × 15 + 6 × 15) × 2 = 480 square centimeter
A: the area of the trademark is 48 square centimeters
Please accept the answer if you are satisfied. If you don't understand, you can ask. I wish you progress in your study!

A rectangular food box, 18 cm in length, 15 cm in width and 20 cm in height, is pasted with trademark paper around it. How many square centimeters is the area of trademark paper?

2 × (18 × 20 + 15 × 20) = 1320 (square centimeter)

A rectangular food box is 20 cm long, 15 cm wide and 30 cm high. Label paper should be pasted around the food box. What is the area of the label paper
A rectangular food box, factory 20 cm, 15 cm wide, 30 cm high, this food box must be pasted around the trademark paper, the trademark paper area is how much?
How many cubic centimetres of stone does a crow contain? How many cubic centimetres of stone can be put into a cup to drink water?
Crow said: rise 5 cm to drink water
How many cubic centimetres of stone does a crow contain? How many cubic centimetres of stone can be put into a cup to drink water?
Crow said: rise 5 cm to drink water
How to do this problem?

Area of inner label paper: 20 × 30 × 2 + 15 × 30 × 2
=1200+900
=2100 {square centimeter}
Because it said that as long as the paste around, so that the bottom does not paste, is generally like this
The answer is clear
Directly: 5 × 6 × 6
=30×6
=180 {CC}
Oh, I'm in grade five, too
Huanggang small number one student exercise book?
Oh, Ho, Ho

A rectangular biscuit box, 20cm in length, 15cm in width and 30cm in height
2cm is used at the joint. How many square centimeters is the area of this brand paper?

（（20+15）*2+2）*30 = 2160 cm^2

A box of biscuits is 20cm in length, 15cm in width and 30cm in height. Now we need to stick label paper around it. How many square centimeters is the area of this label paper

（15×30+20×30）×2
=1050×2
2100 (square centimeter)
Because it's all around, we don't need to calculate the bottom surface by length × width

A box of biscuits is 20 cm in length, 15 cm in width and 30 cm in height. Now we need to paste the trademark paper around it. If the joint of the trademark paper is 4 cm, what is the area of the trademark paper?

(20 × 30 + 15 × 30) × 2 + 30 × 4, = (600 + 450) × 2 + 120, = 2100 + 120, = 2220 (square centimeter); answer: the area of this brand paper is 2220 square centimeter

A rectangular biscuit box, 20cm long, 15cm wide and 10cm high
If you stick a circle of brand paper on his side, what is the area of this paper at least? If you answer correctly, I will give you 5 fans

20×10×2+15×10×2
=400+300
=700（cm2）
A: the area of this paper is at least 700cm2

A kind of juice box is 20cm long, 15cm wide and 30cm high. Now we need to stick the label paper on its outer wall. What's the surface area of the label paper

(20X15 + 20x30 + 15x30) x2 = 1350x22700 (cm2)