The area of a rectangle is 66.5 square cm, and its bottom length is 2.8 square cm

The area of a rectangle is 66.5 square cm, and its bottom length is 2.8 square cm

66.5/2.8=23.75cm

When the side length of a square increases by 3cm, the area increases by 45 square cm. What is the original area of the square?

(x + 3) ^ 2 = x ^ 2 + 45 x = 6 (minus 6 rounded off) 6 * 6 = 36 the original square area is 36 square centimeters

If the side length of a square is increased by 3cm, its area will be increased by 63cm2. Find the current side length and area of the square

According to the meaning of the question: (a + 3) 2-A2 = 63, that is, (a + 3 + a) (a + 3-A) = 3 (2a + 3) = 63, the solution is: a = 9, then the square is now 12 cm in length and 144 cm2 in area

When the side length of a square increases by 3cm, its area increases by 39cm2. The side length of the square is ()
A. 5cmB. 6cmC. 8cmD. 10cm

Let the original side length of the square be x, then x2 + 39 = (x + 3) 2, the solution is x = 5, so a