## Aptitude :: Equation ProblemsPage 3

17.

 In each of the equations, two equations numbered 1 and 2 are given. You have to solve both the equations- 1. 9X - 15.45 = 54.55 + 4X 2. âˆšY +155 - âˆš36 = âˆš49 (a)X < Y (b)X > Y (c)X â‰¤ Y (d)X = Y
9X - 15.45 = 54.55 + 4X
9X - 4X = 54.55 + 15.45
5X = 70.00
X = 14
Again
âˆšY +155 - âˆš36 = âˆš49
âˆšY +155 - 6 = 7
âˆšY + 155 = 7 + 6
âˆšY +155 = 13
Y = 169 - 155
Y = 14

18.

 In each of the equations, two equations numbered 1 and 2 are given. You have to solve both the equations- 1. X² + 11X + 30 = 0 2. Y² + 7Y + 12 = 0 (a)X < Y (b)X > Y (c)X â‰¤ Y (d)X = Y
X² + 11X + 30 = 0
X² + 6X + 5X + 30 = 0
X(X + 6) + 5(X + 6) = 0
(X + 6)(X + 5) = 0
X = -6, -5
Again
Y² + 7Y + 12 = 0
Y² + 4Y + 3Y + 12 = 0
Y(Y + 4) + 3(Y + 4) = 0
(Y + 4)(Y + 3) = 0
Y = -4, -3

19.

 In each of the equations, two equations numbered 1 and 2 are given. You have to solve both the equations- 1. X² + X -12 = 0 2. Y² - 5Y + 6 = 0 (a)X < Y (b)X > Y (c)X â‰¤ Y (d)X = Y
Answer is: CSolve:- X² + X -12 = 0
X² + 4X - 3X -12 = 0
X(X + 4) - 3(X + 4) = 0 (X + 4)(X - 3) = 0 X = 3, -4 Again Y² - 5Y + 6 = 0 Y² - 3Y - 2Y + 6 = 0 Y(Y - 3) - 2(Y - 3) = 0 (Y - 3)(Y - 2) = 0 Y = 3, 2

20.

 In each of the equations, two equations numbered 1 and 2 are given. You have to solve both the equations- 1. X² + 9X + 18 = 0 2. Y² - 13Y + 40 = 0 (a)X < Y (b)X > Y (c)X â‰¤ Y (d)X â‰¥ Y
X² + 9X + 18 = 0
X² + 6X + 3X + 18 = 0
X(X + 6) + 3(X + 6) = 0
(X + 6)(X + 3) = 0
X = -6 , -3
Again
Y² - 13Y + 40 = 0
Y² - 8Y - 5Y + 40 = 0
Y(Y - 8) - 5(Y - 8) = 0
(Y - 8)(Y - 5) = 0
Y = 8, 5