Exercise Simplify. 2(3 • 4)
Exercise Simplify. (5 x 3)6
Exercise Simplify. (4 + 10) + 7
Exercise Simplify. 6 + (2 + 11)
Exercise Simplify. x(4 + 10)
Example 1 Simplify. 2(3n) = 6n
Example 2 Simplify. (x + 2) + 9 = x + 11
Constant A constant is a number whose value does not change.
Term A term is a constant, a variable, or the product of a constant and one or more variables. Terms are always separated from each other by a plus or minus sign.
Numerical Coefficient A numerical coefficient is the number factor (constant) accompanying the variable in a term.
3x + 2y − 4
Parts of an Expression 2x3y + 6 2 is the coefficient. x and y are variables. 3 is an exponent. 6 is a constant.
Example 3 Use the −6xy + − z to answer the following. 2 Use the −6xy + − z to answer the following. What are the terms of the equation? −6xy, , and −z x 2
Example 3 Use the −6xy + − z to answer the following. 2 Use the −6xy + − z to answer the following. Does the expression have a constant term? No. All terms contain a variable factor.
Example 3 Use the −6xy + − z to answer the following. 2 Use the −6xy + − z to answer the following. What are the coefficients in the expression? The coefficients are −6, , and −1. 1 2
Like Terms Like terms are terms that have the same variable (or variables) with the same exponents.
Like Terms 5x, −7x, x 1 2 5xy2, −7xy2, 0.75xy2
Unlike Terms 4x, 4x2 6xy, −8xy3
2y + 7y + 3y
Example 4 Simplify. 7x + 4x = (7 + 4)x = 11x
Example 5 Simplify. 2x + 7y + 3 – y + 5x = = (2x + 5x) + (7y – y) + 3
Exercise Simplify. 5r + 8s − 2r + 3s = 3r + 11s
Exercise Simplify. y + 11 − 5y + 4 − 3y = −7y + 15
Exercise Simplify. 6w − 8x − 2w + 3 − 4x = 4w − 12x + 3
Exercise Simplify. −5a + 3z + 2a + 6z = −3a + 9z
Exercise Simplify. 8c + 5y − 2c + 9y = 6c + 14y
Exercise A rectangle has consecutive sides that are represented by x and x+3. Find the expression that represents the perimeter of the rectangle.
Exercise The sides of a triangle are represented by x, 2x, and 2x − 5. Find the expression that represents its perimeter.
Exercise A farmer has a rectangular pasture with dimensions x by 2x. If he places posts 15 ft. apart, how will he represent the distance between each post on the shorter side? on the longer side?
Exercise Each side of a regular octagon (all sides equal in length) is represented by 14x. Find the expression that represents the perimeter of the regular octagon.
Exercise The side of a square is 4 in. shorter than one side of a given rectangle. The side of the rectangle is represented by 2x + 3. Find the expression that represents the perimeter of the square.