Combining Like Terms<span> Lessons. A </span>term<span> is a constant or a variable in an expression. In the equation 12+3x+2x</span>2<span>=5x-1, the </span>terms<span> on the left are 12, 3x and 2x</span>2<span>, while the </span>terms<span> on the right are 5x, and -1.</span>
