1.

What is the difference in the value of 4x – 3y where x and y are width and length of the rectangle whose perimeter is 60 cm and area is 216? [Consider Length > Width]1). -62). 123). 64). -12

Answer»

Length of rectangle = y cm

Width of rectangle = x cm

Area of rectangle = Length × width

⇒ 216 = y × x

⇒ x = 216/y----(I)

PERIMETER of rectangle = 2(Length + width)

60 = 2(y + x)

⇒ 30 = y + x

Substitute the value of Eq. (I) in above Equation,

⇒ 30 = y + 216/y

⇒ 30y = y2 + 216

⇒ y2 – 30y + 216 = 0

⇒ y2 – 18y – 12y + 216 = 0

⇒ y (y – 18) – 12 (y – 18) = 0

⇒ (y – 18) (y – 12) = 0

⇒ y = 18 [? Length is larger than width]

⇒ x = 216/18 = 12

∴ Required value = 4x – 3y = 4(12) – 3(18) = 48 – 54 = -6


Discussion

No Comment Found

Related InterviewSolutions