If x : y = 7 : 5 and y : z = 4 : 4 , then find x : z

If (x + y)/2 = (y+z)/3 = (z + x)/4 , then find x : y: z .

If 2x = 3y = 4z, find x:y: z.

2x + 3y-5z = 7, x + y + z = 6,3x-4y + 2z = 1, then x =

If x = 1, y = 2, z = 5 , then find the value of 3x – 2y + 4z.

Find the angle between the planes : (i) 3 x - 6y - 2z = 7 " " 2x + y - 2z = 5 (ii) 4 x + 8y + z = 8 " " and y + z = 4 (iii) 2 x - y + z =6 " " and x + y + 2z = 7 .

x y : y z : z x = 1 : 5 : 9 Find ( x + y ) : ( y + z ) : ( z + x ) = ?

Taking x = (-4)/( 9) , y = (5)/( 12) and z = (7)/( 18) , find: (x-y) + z

Taking x = (-4)/( 9) , y = (5)/( 12) and z = (7)/( 18) , find: x- (y +z)