Question

Subtract the sum of 4x +5y +7z,; -y -3z- 5x;, 2z+3x-3y from the sum of -7z +5x -3y,; 15x -12y +3z

Answer 1

Answer:

step 1:

calculate the two sums first

$4x +5y +7z + -y -3z- 5x + 2z+3x-3y \\ = 4x - 5x + 3x + 5y - y - 3y + 7z - 3z + 2z \\ =2x + y + 6z....(2)$$-7z +5x -3y + 15x -12y +3z = - 4z + 20x - 15y....(1)$

step 2:

Now subtract the two sums

Hence (1)-(2) we get,

$- 4z + 20x - 15y - (2x + y + 6z) \\ = - 4z + 20x - 15y - 2x - y - 6z \\ = - 10z + 18x - 16y$