Find the value of k, if `81y^2-k =(9y+1/2)(9y-1/2)`

Find the value of the expression 25 x^(2) + 9y^(2) + 30 xy . When x = 8 and y = 10.

Find the value of k if the points (1, 3) and (2, k) are conjugated with respect to the circle x^(2)+y^(2)=35 .

If the lines (x-1)/2=(y+1)/3=(z-1)/4 and (x-3)/1=(y-k)/2=z/1 intersect then the value of k is (A) 3/2 (B) 9/2 (C) -2/9 (D) -3/2

If the lines (x-1)/2=(y+1)/3=(z-1)/4 and (x-3)/1=(y-k)/2=z/1 intersect then the value of k is (A) 2/9 (B) 9/2 (C) 0 (D) -1

Find the value of (( x -y )^3 + ( y - z )^3 + ( z - x )^3 )/ (9 ( x - y )( y - z ) ( z - x )) 1 . 0 2 . 1/9 3 . 1/3 4. 1

Find the value of x and y I. 18x^(2)-9x+1=0 II. 12y^(2)-y-1=0

Find the value of k, if x=2,y=1 is a solution of the equations 2x+3y=k

Find the value of 'K' for which lines (K-1) x+y - 2 = 0 and (2-K) x - 3y + 1 = 0 are paraller ?

Find the real values of x and y for which z_(1)=9y^(2)-4-10ix and z_(2)=8y^(2)-20i are conjugate complex of each other.

If x+y+z=2k then find the value of [(k-2x)^2+(k-2y)^2+(k-2z)^2+5k^2]/(x^2+y^2+z^2)