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To evaluate an expresion means to find its value To avoid confusion, mathematicians have agreed to a set of called the order of operations. When you a number for the variable, an algebraic expression becomes a numericalexpression. A variable is a , usually a letter, used to represent a . An algebraic expression contains a , a number, and at least one symbol. substitute ? number ? symbol ? operation ? variable ? numeric ? Evaluate each expression if q = 5, r = 6 and s = 3. 4(r - s)2 =4 = 4 ( )2 = 4 x = ( 36 ? 6 ? 9 ? 3 ? - 3 )2 ← ← ← Perform operations in the first. Evaluate the power. Simplify Replace with 6 and with 3. parentheses ? s ? r ? Expressions such a 72 and 23 are called powers and represent repeated Remember q = 5, r = 6 and s = 3. = ( q2 - 4r - 1 5 ? = = = ) 2 25 25 ? 1 ? - 4 - - 4(6) -1 - 1 ( 24 ? 6 ? ) - 1 - 1 ← replace the q with 5 replace the r with 6 Since you have no parentheses you must evaluate the exponents first Work from left to right when operations are the same. |