I. x + 2y + 3z = 2
II. x + y - z = 0
III. 2x + 2y - z = 1
What is the value of y in the system above? Choose the correct choice from the following options
A) -2  B) -1  C) 0  D) 1  E) 2
1. from the given system of equations i can make equation II. to be x + y = z   2. now put that in III. :   2x + 2y - (x + y) = 1   = 2x + 2y - x - y = 1   = x + y = 1   that gives usz = 1!   3. put z = 1 in I. and solve:   x + 2y + 3 = 2; calculate minus 3   = x + 2y = -1; calculate minus x   =2y = -1 - x;   4. now put 2y = -1 - x in III. and solve:   2x + (-1 - x) - 1 = 1   = x - 2 = 1; calculate plus 2   that gives usx = 3   5. now solve for y with x = 3 and z = 1:   x + y = 1   = 3 + y = 1; calculate minus 3   that gives y = -2, and hence answer (-2) -2
<result>A</result>
I. x + 2y + 3z = 2
II. x + y - z = 0
III. 2x + 2y - z = 1
What is the value of y in the system above?