1.The smallest of three consecutive positive integers is m, and the product of the other two integers is m+10. What are the three numbers?
Use the method of taking square roots to solve the quadratic equations involved in the following questions.
2. The length of a rectangle is 3 times its width. If the area of the rectangle is 129 cm2, find the length of the rectangle, correct to 3 significant figures.
3. A small square of sides 4 cm is cut from each of the four corners of a square card. The remaining part of the card can be folded to from a box without a lid. If the capacity of the box is 400cm3, find the length of each side of the original square card.
Use the quadratic formula to solve the quadratic equations involved in the followiing questions.
4. The sum of two numbers is 4, and the sum of their squares is 8.5. Find the two numbers.
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This part, you can use any method to solve the quadratic equation involved in the question.
1. A straight river flows along one side of a rectangular piece of land of area 1200 m2. The other three sides of the land are surrounded by a fence of total length 100 m. Find the length and the width of the piece of land.
更新1:
n = (8 2)/4 ------but 8x2 =16 and 16/4=4 , so why n=2.5 or n=1.5 n = 2.5 or n = 1.5 4 - n = 1.5 or 4 - n = 2.5
