Quadratic Equations for SBI PO 2017

 Direction (Q.1-5): In each of these questions two equations numbered (I) and (II) are given. You have to solve both the equations and give answer:

a) If x > y
b) If x > y
c) If x < y
d) If x < y
e) If x = y or no relationship can't be established between x and y.

Ques 1.

I. x²- 4x - 621 = 0
II. y² - 56y + 783 = 0

Solution: d

I. x² - (27-23)x-621=0

x² - 27x - 23x - 621=0

x (x-27) +23 (x-27)=0

(x-27) (x+23)=0

x=27, x= -23

II. y² - (29+27) y+783 = 0

y² - 29y - 27y + 783 =0

y (y-29) -27(y-29)=0

(y-29) (y-27) =0

y=29, y=27

Ques 2.

I. 15x² - 34x + 15 = 0
II. 15y² + 22y + 8 = 0

Solution: a

I. 15x²- (9+25)x + 15 =0

15x² - 9x - 25x + 15 = 0

3x (5x-3)-5 (5x-3)=0

(3x-5) (5x-3)=0

II. 15y² +(10+12)y + 8 = 0

15y² + 10y + 12y + 8 = 0

5y (3y+2) +4 (3y+2)=0

(3y+2) (5y+4)=0

Ques: 3

I. x² = 121
II. y³ =1331

Solution: d

Ques : 4

I. x² + 12x + 35 = 0
II. y² + 18y + 45 = 0

Solution: e

I. x² + (7+5)x + 35 = 0

x² + 7x + 5x + 35 =0

x (x+7) +5 (x+7)=0

(x+7) (x+5) = 0

x= -7, x=-5

II. y² + (15+3) +45=0 

y² + 15y + 3y + 45=0

y (y+15)+3 (y+15)=0

(y+15) (y+3) = 0

y= -15, y=-3

Ques: 5

I. 14x² -41x + 15=0
II. 56y² - 54y+ 10 = 0

Solution: e

I. 14x² - (35+6)x +15=0

14x² -35x -6x+15=056

7x (2x-5)-3 (2x-5)=0

(2x-5) (7x-3)=0

II. 56y²- (40+14)y +10=0

56y² - 40y- 14y +10=0

8y(7y-5)-2(7y-50=0

(7y-5) (8y-2) =0