Answer:
No solution.
Step-by-step explanation:
So lets solve the square root.
Sqrt(y^2 - 20 + 100) = y - 10
Sqrt(y^2 + 80 = y - 10)
Solve time.
y^2 + 80 = y - 10 (We are squaring them)
y^2 + 80 = y^2 - 20y + 100
y^2 + 80 - y^2 = y^2 - 20y + 100 - y^2 (Subtract y^2 from both sides)
80 = -20y + 100
Flip it
-20y + 100 = 80
-20y + 100 - 100 = 80 - 100 (Subtract 100 from both sides)
-20y = -20
Now divide both sides by -20
-20y/-20 = -20/-20
y = 1
All you would do is plug in the values and you get...
This is false.