Answer:
6x+21 (Maybe)
Are you doing the buddy method, how is your teacher wanting to do this, When you respond I might have the correct answer
(buddy method) Multiply the 2x and 7 by the 3 giving you 6x+21 and then that's it you cant do anything else but I don't know if that's how you're teacher wants it done.
Y=4 or -4
Explanation: trust me bro
For the lines to be parallel the two angles need to be equal to each other:
128-x = x
Add 1x to both sides
128 = 2x
Divide both sides by 2:
X = 128/2
X = 64
Answer: x = 64
Y=mx+b
so is 2
the last number of the equation