1）The sum of the area s of two circles is 65pi square feet.T

来源：学生作业帮编辑：搜搜考试网作业帮分类：数学作业时间：2024/07/12 12:29:10

1）The sum of the area s of two circles is 65pi square feet.The length of a radius of the larger circle is one foot less than twice the length of the radius of the smaller circle.Find the length of a radius of each circle.
2)
The combined area of a square and a rectangle is 64 square centimeters.The width of the rectangle is 2 cm more than the length of a side of the square and the length of the rectangle is 2 cm more than its width.Find the dimensions of the square and the rectangle.
3)
The Ortegas have an apple orchard that contains 90 trees.The number of trees in each row is 3 more that twice the number of rows.Find the number of rows and the number of trees per row?

1、大圆小圆面积总和是65,大圆半径比小圆半径的2倍少1,求每个圆半径.
设小圆半径为r,大圆半径为2r-1,
则 πr^2+π(2r-1)^2=65
解出r后再求2r-1即可
2、正方形和矩形面积之和为64.长方形的宽比正方形边长大2,长方形的长比宽多2,求两个图形各自的边长.
解
设长方形宽为x,则长为x+2,正方形边长为x-2
所以
x(x+2)+(x-2)^2=64
2x^2-2x-60=0
x^2-x-30=0
x=6
所以正方形边长为4,长方形长为8,宽为6.
3、某人有一个苹果园,种有90棵树.每一行苹果树的数量比果园的总行数2倍多3.求每行苹果树的数目以及果园共有多少行.
解
设果园有x行,则每行苹果树为2x+3,
90=x(2x+3)
2x^2+3x-90=0
x=6
所以共有6行,每行15棵树.

1）The sum of the area s of two circles is 65pi square feet.T What is the sum of their area? Given that A is the sum ofthe square of 3 and the square of The area of it is 467000 square metres.(划线部分提问） _____ _____ 英语翻译if the number of square units in the area of circle C is 英语翻译What fractional part of the area of the square is shaded How many square meters is the area of the dog that the goat 翻译What’s the area of the Congo in square miles? The area of the city is nearly 352 square kilometers populat 英译汉is dimensioned so that the sum of these two energies (U,s The sum of two even numbers is always what? The sum of two facing pages of a book is 342.Find the two pa