If you try to solve the equation and one of the variables is suddenly eliminated, then you can see if it results in a true or false statement.
Start by simplifying both sides and then try plugging in different values to test it.
Simply put,
x=x
is an equation that is always true,
1=2
is an equation that is always false, and
x2=4is an equation that is sometimes true.
Another example:Try to solve 3(2x+9) = 6x + 16. What happens? This equation has no solutions, because the variables cancel and you get 27 = 16, which is false. So this equation is never true