if x-y-z = 0,3 x+4y+3z = 4,5x+2y+7z = 22 ,what is the value of z? Choose the correct choice from the following answers:	A) 3	B) 4	C) 5	D) 2	E) 1
Explanation:   4x + 2y - 5z = - 21 â€“-------I   2x - 2y + z = 7â€“------ II   4x + 3y - z = - 1-------- III   Solve the first equation for x.   x-y-z = 0   x = y+z   Substitute the solution for x into the second and third equations.   II---&gt; 3*(y+z)+4y+3z = 4   3y+3z+4y+3z = 4   7y+6z = 4   III----&gt;5*(y+z)+2y+7z = 22   5y+5z+2y+7z = 22   7y+12z = 22   Subtract the new second equation from the new third equation and solve for z.   7y+12z = 22   - (7y+6z = 4)   6z = 18   z=3   3nswer is 3
<result>A</result>
if x-y-z = 0,3 x+4y+3z = 4,5x+2y+7z = 22 ,what is the value of z?