Find the following products:
(i) `(0. 9 x+0. 7 y)(0. 81 x^2-0. 63 x y+0. 49 y^2)`
(ii)`((2x)/5-(3y)/7)((9y^2)/(49)+(4x^2)/(25)+(6x y)/(35))`

Find the product: (0. 9 x+0. 7 y)(0. 81 x^2-0. 63 x y+0.49 y^2)

Find the following products: (6x)/5(x^3+y^3) (ii) x y(x^3-y^3) (iii) 0. 1 y(0. 1 x^5+0. 1 y)

{:(0.4x + 0.3y = 1.7),(0.7x - 0.2y = 0.8):}

Factorise the following : (i) 9a^(2)-b^(2) " " (ii) 81x^(3)-x " " (iii) x^(3)-49xy^(2) " " (iv) a^(2)-(b-c)^(2) (v) (x-y)^(3)-x+y " " (vi)x^(2)y^(2)+1-x^(2)-y^(2) " " (vii) 25(a+b)^(2)-49(a-b)^(2) " " (viii) xy^(5)-x^(5)y (ix) x^(8)-256 " " (x) x^(8)-81y^(8)

Add the following (i) 7abc , -5abc , 9abc , -8abc (ii) 2x^2y , -4x^2y , 6x^2y , -5x^2y

Solve the following pair of linear equatio: 3x-5y-4=0 9x=2y+7

Find the centre and radius of each of the following circle : (i) x^(2)+y^(2)+4x-4y+1=0 (ii) 2x^(2)+2y^(2)-6x+6y+1=0 (iii) 2x^(2)+2y^(2)=3k(x+k) (iv) 3x^(2)+3y^(2)-5x-6y+4=0 (v) x^(2)+y^(2)-2ax-2by+a^(2)=0

Factorize following experssions (i) x^(4)-y^(4)" (ii)"9a^(2)-(2x-y)^(2)" (iii)"4x^(2)-9y^(2)-6x-9y

Find the centre and radius of the circle 3x^(2) +3y^(2) - 6x +9y - 8 =0 .

The equation of the incircle of the triangle formed by the coordinate axes and the line 4x + 3y - 6 = 0 is (A) x^(2) + y^(2) - 6x - 6y - 9 = 0 (B) 4 (x^(2) + y^(2) - x - y) + 1 = 0 (C) 4 (x^(2) + y^(2) + x + y) + 1 = 0 (D) 4 (x^(2) + y^(2) - x - y ) - 1 = 0