AccelePrep for the ACT Test 2nd Edition Student Text

104 • S URGE TO S UCCESS ! M ATH T EST P REP

ALGEBRAIC OPERATIONS

SUBSTITUTE AND SOLVE

You may be asked to evaluate or manipulate algebraic expressions, solve equations, and even create equations. Many of these items are fairly straightforward and can be answered using the basic algebraic procedures that you learned in math class. 1. If x = 2, what is the value of x x 2 1 2 ? A. –4 B. –2 C. 0 D. 1 E. 2 ‘™ Ž‡–ǯ• Ž‘‘ ƒ– ƒ ‹–‡ –Šƒ– ‹• ƒ „‹– ‘”‡ †‹ˆϐ‹…—Ž–Ǥ – ‹• ‘”‡…ŠƒŽŽ‡‰‹‰ because it uses function notation, but the procedure is the same. 2. If ( ) f x x 3 and ( ) g x x 2 5 , what is the value of ( ( )) f g 2 ? F. –2 G. 0 H. 2 Ǥ Ͷ K. 10 Let’s call this process of plugging in the values given in the item stem “Substitute and Solve.” Substitute and Solve is a good approach for items ™Š‡”‡ ƒ ˜ƒŽ—‡ ‹• ’”‘˜‹†‡† ˆ‘” ›‘— –‘ –‡•–Ǥ —– ™Šƒ– ‹ˆ –Š‡”‡ ‹• ‘ •’‡…‹ϐ‹… value? ˆ ›‘— ƒ”‡ ‘– ‰‹˜‡ ƒ •’‡…‹ϐ‹…˜ƒŽ—‡ǡ Ž—‰Ǧƒ†Ǧ Š—‰Ǥ Š‘‘•‡ ›‘—” ‘™ values to test. Calculate the solution for the expression given in the item stem, then test the answer choices using the value(s) you chose. The correct answer choice will return a numerical value that is equal to that returned by the expression in the question stem. It’s actually easier to demonstrate.

Example:

STRATEGY ALERT If you are given a value, substitute and solve.

Example:

Explanations for the example questions are included later in the chapter. Circle your answers now. Later when you reach the explanations at the end of the section, come back and check to make sure you answered the questions correctly.

PLUG-AND-CHUG