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 

Answer is: DSolve:
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 

Answer is: ASolve:
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 

Answer is: BSolve :
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
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