It gives you an irrational number, a decimal. It's not a perfect square like

or

.
Answer:
40/3
Step-by-step explanation:
4x -20 = 10x -100 (Distributive Property)
4x -10x = -100 +20 (I swith the numbers so all of them are similar)
-6x= -80 (Divide -6 on both sides)
And you will get 40/3 or 13.3333..
Well what you do is move the 2x over to the other side to make y=mx+b. It should look like this: -5y=-2x+11. Then you replace the x with 2,it should now look like this: -5y=-2(2)+11. Then you simplify and get this: -5y= 7. Then you divide -5 by both sides and get: y= 1.4 or 1 2/5. Hope that helped! If this is wrong to you double check the question you wrote.
Answer: The answer equals 0