solve the equation if it an identity (all real numbers) or a contradiction please state

Question

5x+6+6x=10x+6+y

Answer 1

The eqution reduces to
y = x

Solving an equation means to find the values of the variable that make the equation true
There will be an infinite number of solutions, as long as the x value is equal to the y value
e.g.
x = 67, y = 67 works
x = √37 + 6.5 , y = √37 + 6.5 works
etc

Answer 2

X=5X+6Y