I. ` 7x + 6y = 110`
II. ` 4x + 3y = 59`
III.` X + z = 15`

I. 8x+7y = 135" " II. 5x+6y = 99 III. 9y+8z= 121

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 .

Prove that the lines 3x + 2y + z – 5 = 0 = x + y – 2z – 3 and 2x – y – z = 0 = 7x + 10y – 8z – 15 are perpendicular

If 7x + 6y - 2z = 0, 3x + 4y + 2z = 0, x - 2y - 6z = 0 then which option is correct

If 7x + 6y - 2z = 0, 3x + 4y + 2z = 0, x - 2y - 6z = 0 then which option is correct

Solve the following system of linear equation by matrix method : 5x + y - z = - 6, 2x - 3y + 4z = 3, 7x + y - 3z = - 12.

Do the following equations represent a pair of coincident lines ? Justify your answer. (i) 3x + (1)/(7)y = 3 and 7x + 3y = 7 (ii) -2x - 3y = 1 and 6y + 4x = -2 (iii) (x)/(2) + y + (2)/(5) = 0 and 4x + 8y + (5)/(16) = 0