If the area of the rectangle is x2 - 20x + 91, then find its perimeter.
Correct Answer : a ) 4x – 40Explanation :
According to the question
Area of the rectangle = x2 - 20x + 91
We know that
Area of the rectangle = L × B …….(a)
Where L and B are the length and breadth of the rectangle
⇒ x2 - 20x + 91
⇒ x2 - 13x - 7x + 91
⇒ x(x - 13) - 7(x + 13)
⇒ (x - 13) × (x - 7)
⇒ Area of the rectangle = (x - 13) × (x - 7) …….. (b)
On Comparing eq(a) and (b) we get
L = (x - 13) and B = (x - 7)
We know that
Perimeter of the rectangle = 2 * (L + B)
Substituting the value of L and B
⇒Perimeter of the Rectangle = 2 * [(x - 13) + (x - 7)]
⇒ 2 *( x – 13 + x – 7)
⇒ 2 * (2x - 20)
⇒ 4x – 40
Thus, the perimeter of the rectangle = 4x – 40
Hence, (a) is the correct answer.
Such type of question is asked in various government exams like SSC CGL, SSC MTS, SSC CPO, SSC CHSL, RRB JE, RRB NTPC, RRB GROUP D, RRB OFFICER SCALE-I, IBPS PO, IBPS SO, RRB Office Assistant, IBPS Clerk, RBI Assistant, IBPS RRB OFFICER SCALE 2&3, UPSC CDS, UPSC NDA etc.
Read Daily Current Affairs, Banking Awareness, Hindi Current Affairs, Word of the Day, and attempt free mock tests at PendulumEdu and boost your preparation for the actual exam.
Word Of The Day
Noun: A hard rigid usually large covering of an animal.; The outside part of a fruit or seed.; Something like an external structure that resembles a shell.; A casing without substance.; The hard exterior of an egg.; A hard enclosing cover.
Verb: To take out of the shell.; To fall out of the shell.; To cast the external covering.; To gather shells from a beach.
"My mother collected shells at the beach."View More