Algebra Demystified 2nd Ed

246 algebra De mystif ieD If the difference between two numbers is 13, then one of the numbers is 13 more than the other. As bef ...

Chapter 8 linear appliCaTionS 247 PRACTICE The sum of two numbers is 10. Three times the smaller plus five times the larger num ...

248 algebra De mystif ieD is x + 8. One and a half of the smaller number is 112 x; four times the larger is 4(x + 8). 11 2 4854 ...

Chapter 8 linear appliCaTionS 249 EXAMPLE Jill is twice as old as Jim and Jim is 3 years older than Ken. The sum of their ages i ...

250 algebra De mystif ieD PRACTICE Andy is 3 years older than Bea and Bea is 5 years younger than Rose. If Rose is 28, how old ...

Chapter 8 linear appliCaTionS 251 Monica’s earnings are being compared to John’s, and John’s to Alicia’s. The easiest thing to ...

252 algebra De mystif ieD Angela has grades of 78, 83, 86, 82, and 88. If the next grade counts twice as much as each of the oth ...

Chapter 8 linear appliCaTionS 253 Let x represent the project grade. 2 3 87 1 3 90 58 3 90 358 3 390 3583 () () () += +=  +  ...

254 algebra De mystif ieD ✔SOLUTIONS Let x = the next grade. 93 89 96 98 5 95 376 5 95 5376 5 595 37 ++++= + =  +    = x ...

Chapter 8 linear appliCaTionS 255 Let x represent Ava’s final exam grade. Her test average is (68 + 73 + 80 95)/4 = 79. Then^13 ...

256 algebra De mystif ieD 1488 4 540 2400 2028 4 2400 2028 2028 4 372 3 ++= += −− = = x x x x^772 4 x= 93 The student needs a 93 ...

Chapter 8 linear appliCaTionS 257 EXAMPLE Terri has $13.45 in dimes and quarters. If there are 70 coins in all, how many of each ...

258 algebra De mystif ieD The total amount of money is $1.54, so 02. 50 ... 20 030002 15. 4 ( x +++=xxx amountin (amountinn(amou ...

Chapter 8 linear appliCaTionS 259 Let x represent the number of quarters. There are as many dimes as quarters, so x also repres ...

260 algebra De mystif ieD HINt If we let x represent the amount earned at interest rate A, then the rest is invested at interest ...

Chapter 8 linear appliCaTionS 261 PRACTICE A businessman invested $50,000 into two funds which yielded profits of 1621 % and 18 ...

262 algebra De mystif ieD Let x represent the amount deposited at 434 %. Then the amount depos- ited at^541 % is 3500 − x. The ...

Chapter 8 linear appliCaTionS 263 peanut mixture to obtain a 50% peanut mixture. You might have a two-cycle engine requiring a p ...

264 algebra De mystif ieD EXAMPLE How much 10% acid solution should be added to 30 liters of 25% acid solution to achieve a 15% ...

Chapter 8 linear appliCaTionS 265 Let x represent the amount of 10% acid solution, so 100 – x represents the amount of 30% acid ...