Quadratic Equation
Direction: In each of the following question, there are two equations. you have to solve both equations and give answer.
- x2 - 16 = 0 y2 - 9y + 20 = 0
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x2 - 16 = 0
⇒ x2 = 16 ⇒ x = √16 = ± 4
and y2 - 9y + 20 = 0
y2 - 4y - 5y + 20 = 0
⇒ y(y - 4) - 5(y - 4) = 0
⇒ y = 5, 4
⇒ y ≥ x or x ≤ yCorrect Option: D
x2 - 16 = 0
⇒ x2 = 16 ⇒ x = √16 = ± 4
and y2 - 9y + 20 = 0
y2 - 4y - 5y + 20 = 0
⇒ y(y - 4) - 5(y - 4) = 0
⇒ y = 5, 4
⇒ y ≥ x or x ≤ y
- x2 - 32 = 112; y - √169 = 0
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x2 - 32 = 112
⇒ x2 = 112 + 32 ⇒ x2 = 144
∴ x = ± 12
and y - √169 = 0
⇒ y = √169
⇒ y = ± 13
∴ Relation cannot be established.Correct Option: E
x2 - 32 = 112
⇒ x2 = 112 + 32 ⇒ x2 = 144
∴ x = ± 12
and y - √169 = 0
⇒ y = √169
⇒ y = ± 13
∴ Relation cannot be established.
- x2 - 8x + 15 = 0 ; y2 - 3y + 2 = 0
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x2 - 8x + 15 = 0
⇒ x2 - 5x - 3x + 15 = 0
⇒ x(x - 5) -3(x - 5) = 0
⇒ (x - 5) (x - 3) = 0
∴ x = 5, 3
and y2 - 3y + 2 = 0
⇒ y2 - 2y - y + 2 = 0
⇒ y(y - 2) -1(y - 2) = 0
⇒ (y -2) (y - 1) = 0
⇒ y = 2, 1
∴ x > yCorrect Option: A
x2 - 8x + 15 = 0
⇒ x2 - 5x - 3x + 15 = 0
⇒ x(x - 5) -3(x - 5) = 0
⇒ (x - 5) (x - 3) = 0
∴ x = 5, 3
and y2 - 3y + 2 = 0
⇒ y2 - 2y - y + 2 = 0
⇒ y(y - 2) -1(y - 2) = 0
⇒ (y -2) (y - 1) = 0
⇒ y = 2, 1
∴ x > y
- x2 - x - 12 = 0; y2 + 5y + 6 = 0
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Find the value of x and y
Correct Option: B
x2 - x - 12 = 0
⇒ x2 - 4x + 3x - 12 = 0
⇒ x(x - 4) + 3 (x - 4) = 0
⇒ (x - 4) (x + 3) = 0
∴ x = - 3, 4
and y2 + 5y + 6 = 0
⇒ y2 + 3y + 2y + 6 = 0
⇒ y(y + 3) + 2(y + 3) = 0
⇒ (y + 3) (y + 2) = 0
⇒ y = - 3, - 2
∴ x ≥ y
[∵ x = - 3 and y = - 3, so x = y and x = 4 and y = - 2, hence x > y]
- 3x2 + 8x + 4 = 0; 4y2 - 19y + 12 = 0
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3x2 + 8x + 4 = 0
⇒ 3x2 + 6x + 2x + 4 = 0
⇒ 3x(x + 2) + 2(x + 2) = 0
⇒ (x + 2) (3x + 2) = 0
∴ x = - 2, - 2/3
and 4y2 - 19y + 12 = 0
⇒ 4y2 - 16y - 3y + 12 = 0
⇒ 4y(y - 4) -3(y - 4) = 0
⇒ (y - 4) (4y - 3) = 0
∴ y = 4, 3/4
Hence, y > x or x < yCorrect Option: C
3x2 + 8x + 4 = 0
⇒ 3x2 + 6x + 2x + 4 = 0
⇒ 3x(x + 2) + 2(x + 2) = 0
⇒ (x + 2) (3x + 2) = 0
∴ x = - 2, - 2/3
and 4y2 - 19y + 12 = 0
⇒ 4y2 - 16y - 3y + 12 = 0
⇒ 4y(y - 4) -3(y - 4) = 0
⇒ (y - 4) (4y - 3) = 0
∴ y = 4, 3/4
Hence, y > x or x < y