In algebraic expressions, 'like' terms are ones which have the same powers. For example, 3x2,  -5x2,  ¼x2  and x2 are all 'like' terms in power x2 6,  -8,  1  and 11 are all 'like' terms that are constants 7x,  -6x,  ¾x,  12x1,  and x are all 'like' terms in x 2y3,  -y3,  4y3  and -½y3 are all 'like' terms in y3 When combining terms by adding or subtracting, only 'like' terms can be combined For example: 3x2 + 5x2 = 8x2   and   -3y + 5y = 2y but: 6x2 + 4x can't be combined because the exponents are different 5y + 2x can't be combined because the variables are different 4x3 - 6y3 can't be combined because the variables are different The variable (letter) and the exponent on the variable must be the same In a mixed expression, you can only combine the 'like' parts:    3x2 + 4x - 7 + 5x2 + x - 2    The x2, x, and constant terms must be combined separately = 3x2 + 4x - 7 + 5x2 + x - 2 = 8x2 + 5x - 9 A skill you need to do these questions is the ability to mentally add and subtract integers. Here is a worksheet you can use to practice; use a calculator to check your answers. Another example:    4x - 5y2 + y + 11x - 2y2 = 4x - 5y2 + y + 11x - 2y2 = 15x - 7y2 + y      sometimes there is nothing to combine, as with the 'y' term Another example:    2x2 - 3 + 10x2 + 7 - 4x2 - 1 = 2x2 - 3 + 10x2 + 7 - 4x2 - 1 = 8x2 + 3 *** Try a self-checking quiz *** Resources Content, HTML, graphics & design by Bill Willis 2024