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
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...