Algebra Demystified 2nd Ed

206 algebra De mystif ieD Solve for b. Aa=+bh = 1 2 () A(andaaredifferentvariables.) A^11 2 1 2 1 2 1 2 1 2 abh Aah  +    ...

Chapter 7 linear equaTionS 207 V ;= πrh^ h 2 3 P = 2L + 2W; L L = L 0 [1 + a(dt)]; a S = C + RC; C A = P + PRT; R H kAtt L   ...

208 algebra De mystif ieD PLWL PLW WW PWL PWL =+ =+ −− −= − = 22 22 22 22 2 2 ;  LL adta LL adt LL Ladt L =+ =+ =+ 0 0 00 1 ...

Chapter 7 linear equaTionS 209 H kAtt L t H kAtt L HL kAtt HL kAt = − = − =− = ();  () () (^121) 12 12 1 −− ++ += = kAt kAtk ...

210 algebra De mystif ieD Equations Leading to Linear Equations Some equations are almost linear equations; after one or more st ...

Chapter 7 linear equaTionS 211 Anytime we multiply (or divide) both sides of the equation by an expression with a variable in it ...

212 algebra De mystif ieD still struggling Have you ever wondered why expressions such as^20 are not numbers? let us see what co ...

Chapter 7 linear equaTionS 213 square root on one side of the equation (in this example, it already is) and then square both sid ...

214 algebra De mystif ieD Quadratic equations, to be studied in Chapter 10, have their variables squared—that is, the only power ...

Chapter 7 linear equaTionS 215 (x − 7)^2 − 4 = (x + 1)^2 4.^67 41 38 24 x x x x + − = + − 5.^9 31 4 3 31 x xx− =+ − 6.^1 1 2 1 ...

216 algebra De mystif ieD 2.^6 52 9 xx− 76 = + This equation is in the form “Fraction = Fraction,” so cross-multiply. 67 6952 42 ...

Chapter 7 linear equaTionS 217 4.^6741 xx+− =^3824 xx+− This is in the form “Fraction = Fraction,” so cross-multiply. () 67 () 2 ...

218 algebra De mystif ieD 6.^13 1 2 1 2 xx− 1 x − + = − 13 1 11 2 xx− 1 xx − + = ()−+() The LCD is (x − 1)(x + 1). ()() ()() ()( ...

Chapter 7 linear equaTionS 219 2316 2316 x xbefore −+= −+= Isolatethesquareroot ssquaringbothsides. −− −=  −  = − 11 235 2 ...

220 algebra De mystif ieD Summary In this chapter, we learned how to • Use PEMDAS to compute complex expressions. The letters ...

Chapter 7 linear equaTionS 221 Quiz Solve 5 xx −=^1243 +. a. x=^1 6 b. x=−^7 2 C. x=^5 2 D. x=^7 2 Solve^1 23 5 xx+ = + 6 . ...

222 algebra De mystif ieD Solve 3 4 2 4 16 xx+ x^216 + − = −. a. x= 4 b. x=^4 5 C. x=^5 4 D. There is no solution. Solve 12   ...

223 chapter 8 Linear Applications Word problems (also called applications or applied problems) are usually not students’ favorit ...

224 algebra De mystif ieD Percents A percent is a decimal number in disguise. In fact, the word “percent” literally means “per h ...

Chapter 8 linear appliCaTionS 225 Increasing/Decreasing by a Percent As consumers, we often see quantities being increased or de ...