Question
The length of a rectangle is 15 cm more than its width.
If the area of the rectangle is 240 cm², what is the perimeter of the rectangle?Solution
Let the width of the rectangle be x cm. Then, the length of the rectangle = x + 15 cm. Area of the rectangle = length × width = 240 cm² (x + 15) × x = 240 x² + 15x = 240 x² + 15x - 240 = 0 Solving the quadratic equation using the factorization method: (x + 24)(x - 10) = 0 So, x = 10 or x = -24. Since the width cannot be negative, x = 10 cm. Therefore, the length of the rectangle = 10 + 15 = 25 cm. Perimeter of the rectangle = 2 × (length + width) = 2 × (25 + 10) = 2 × 35 = 70 cm Correct Option: d) 70 cm
A certain number of students from school X appeared in an examination and 30% students failed. 150% more students than those from school X, appeared in ...
If 2x + 3y = 19 and 3x - 2y = 9, then the value of x2 + y2 is:
If √x + 1/√x = 2 then find the value of 3x2 + 1/3x2.
If 'x' = √8, then find the value of (x - 2)² + (x + 2)².
If x ,y,z are three integers such that x +y = 8,y +z =13 and z +x =17,then the value of x2 /yz  is:
Find the number of zeroes in 18 × 125 × 20 × 32.
- If 2a + b = 15 and ab = 18, then the value of (4a² - b²) .
(x + 4) 2 + (y – 1) 2 + (z + 2) 2 = 0, then find the value of 2x - 3y + z.