I. 5 12 = 1 𝑥– 𝑥2 2 II. 2 + 20 = 13 𝑦2 𝑦

Explanation

I. 5 – 12 = 1 x x2 2 Multiply by 2x² 10x – 24 = x² ⇒ x² – 10x + 24 = 0 ⇒ x² – 6x – 4x + 24 = 0 ⇒ x (x – 6) – 4 (x – 6) = 0 ⇒ (x – 4) (x – 6) = 0 ⇒ x = 4, 6 7 www.bankersadda.com | www.ssca II. 2 + 20 = 13 y2 y Multiply by y² 2y² + 20 = 13y ⇒ 2y² – 13y + 20 = 0 ⇒ 2y² – 8y – 5y + 20 = 0 ⇒ 2y (y – 4) –5 (y – 4) = 0 ⇒ (2y – 5) (y – 4) = 0 ⇒ y = , 4 x ≥ y S70. Ans.(c) Sol. I. 32x+4 = 93x+4 × 27(x+1) 32x+4 = 36x+8 × 33x+3 ⇒ 2x + 4 = 6x + 8 + 3x + 3 ⇒ 7x = –7 ⇒ x = –1 y2+18 II. = 9 y ⇒ y² – 9y + 18 = 0 ⇒ y² – 3y – 6y + 18 = 0 ⇒ y (y – 3) – 6 (y – 3) = 0 ⇒ (y – 6) (y – 3) = 0 y = 6, 3 y > x Sol (71-75): In year 2011, Let number of public vehicles and private vehicles are x and y. 𝑥−𝑦= 250 …. (i) 𝑥+ 𝑦= 850 ….(ii) by equating (i) and (ii) x=550 y=300 Years Public vehicle Private vehicle 2011 550 300 2012 650 400 2013 750 350 2014 500 300 2015 800 400 adda.com | www.careerpower.in | Adda247 App