(i)` x^(2) -18x+72 = 0`
(ii)` y^(2)=36`

(i) x^(2) -10x+21 = 0 (ii) y^(2) -11y+18 = 0

In the following questions two equation numbered I and II are given You have to solve both equations and . . . . . (i) 5x^(2)-18x+9=0 (ii) 20y^(2)-13y+2=0

I. x^(2) - 72 = x" " II. y^(2) = 64

Find the nature of the roots of the equations of given below : (a) x^(2) - 13x + 11 =0 (b ) 18x^(2) - 14x + 17 = 0 (c ) 9x^(2) - 36x + 36 = 0 (d) 3x^(2) - 5x - 8 = 0

I. x^(2) + 72 = 108" "II. Y^(2) = 6

Prove that the centres of the circles x^(2) + y^(2) - 10x + 9 = 0, x^(2) + y^(2) - 6x + 2y + 1 = 0 and x^(2) + y^(2) - 18x - 4y + 21 = 0 lie on a line, find the equation of the line on which they lie.

Factorise the following : (i) x^(2)+7x+12 " " (ii) x^(2)+18x+45 " " (iii) x^(2)-7x+12 " "(iv) x^(2)-25x-84

I. x^(2) + 17x+72 = 0" " II. y^(2) + 19y + 90 = 0

Solve each of the following equations by using the formula : (i) 5x^(2)-2x-3=0 (ii) x^(2)=18x-77

In the following questions two equation numbered I and II are given You have to solve both equations and . . . . . (i) x^(2)+12x=-36 (ii) y^(2)+15y+56=0