SOLUTION: Identify whether it is an expression or equation: -7c + 6d -3ab + 6 =2c + b

An equation always contains an equal sign "=".
But an Expression does not.

Look at 



See the equal sign =?  What does that tell you?

Now what's on the left side of the = sign



is an expression, and what's on the right side
of the = sign 



is also an expression, because they do not contain
an = sign.  But



contains an equal sign, so it is an equation.

Edwin