New SAT Math Workbook

# Com 118 chapter 8 exercise 1 work out each problem

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Unformatted text preview: t each problem. Circle the letter that appears before your answer. 1. At 8 a.m. the temperature was –4°. If the temperature rose 7 degrees during the next hour, what was the thermometer reading at 9 a.m.? (A) +11° (B) –11° (C) +7° (D) +3° (E) –3° In Asia, the highest point is Mount Everest, with an altitude of 29,002 feet, while the lowest point is the Dead Sea, 1286 feet below sea level. What is the difference in their elevations? (A) 27,716 feet (B) 30,288 feet (C) 28,284 feet (D) 30,198 feet (E) 27,284 feet Find the product of (–6)( –4)( –4) and (–2). (A) –16 (B) +16 (C) –192 (D) +192 (E) –98 4. The temperatures reported at hour intervals on a winter evening were +4°, 0°, –1°, –5°, and –8°. Find the average temperature for these hours. (A) –10° (B) –2° (C) +2° (D) (E) 5. –2 –3° 1 ° 2 2. Evaluate the expression 5a – 4x – 3y if a = –2, x = –10, and y = 5. (A) +15 (B) +25 (C) –65 (D) –35 (E) +35 3. www.petersons.com Concepts of Algebra—Signed Numbers and Equations 119 2. SOLUTION OF LINEAR EQUATIONS Equations are the basic tools of algebra. The techniques of solving an equation are not difficult. Whether an equation involves numbers or only letters, the basic steps are the same. 1. If there are fractions or decimals, remove them by multiplication. 2. Remove any parentheses by using the distributive law. 3. Collect all terms containing the unknown for which you are solving on the same side of the equal sign. Remember that whenever a term crosses the equal sign from one side of the equation to the other, it must pay a toll. That is, it must change its sign. 4. Determine the coefficient of the unknown by combining similar terms or factoring when terms cannot be combined. 5. Divide both sides of the equation by the coefficient. Example: Solve for x: 5x – 3 = 3x + 5 Solution: 2x = 8 x=4 Example: Solve for x: Solution: Multiply by 12. 8x – 120 = 3x + 180 5x = 300 x = 60 Example: Solve for x: .3x + .15 = 1.65 Solution: Multiply by 100. 30x + 15 = 165 30x = 150 x=5 2 1 x – 10 = x + 15 3 4 Example: Solve for x: ax – r = bx – s Solution: ax – bx = r – s x(a – b) = r – s x= Ex...
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## This note was uploaded on 08/15/2010 for the course MATH a4d4 taught by Professor Colon during the Spring '10 term at Embry-Riddle FL/AZ.

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