Chapter 1 Solving Linear Equations and Inequalities Exercise Set 1.1 RC2.(f) RC4.(c) 2.47−x=23
47−24?23
23
TRUE 24 is a solution of the equation.
- 3x+14=−27
3(−10)+14 ?−27
−30+14
−16
FALSE −10 is not a solution of the equation.
6.−x 8 =−3 −32 8 ?−3 −4
FALSE 32 is not a solution of the equation.
- 4−5x=59
4−5(−11) ? 59
4+55
59
TRUE −11 is a solution of the equation.
10.9y+5=86
9·9+5?86
81+5
86
TRUE
- is a solution of the equation.
- x+5=5+ x
−13+5 ? 5+(−13)
−8
−8TRUE
−13 is a solution of the equation.
- x+7=14
- −27 =y−17
- −37 +x=−89
- z−14.9=−5.73
- x+
x+7−7=14−7 x+0=7 x=7
−27+17=y−17 + 17 −10 =y+0 −10 =y 18.−8+r=17 8−8+r=8+17 0+r=25 r=25
37−37 +x=37−89 0+x=−52 x=−52
z−14.9+14.9=−5.73+14.9 z+0=9.17 z=9.17
1 12 =− 5 6 x+ 1 12 − 1 12 =− 5 6 − 1 12 x+0=− 10 12 − 1 12 x=− 11 12 26.5x=30 5x 5 = 30 5 1·x= 30 5 x=6 28.−4x= 124 −4x −4 = 124 −4 1·x= 124 −4 x=−31
30. −
x 3
=−25
− 1 3 x=−25 −3 ( − 1 3 f x=−3(−25) x=75 Copyrightcf2015 Pearson Education, Inc.(Intermediate Algebra, 12e Marvin Bittinger, Judith Beecher, Barbara Johnson) (Solution Manual, For Complete File, Download link at the end of this File) 1 / 4
18 Chapter 1:Solving Linear Equations and Inequalities
32.−120 =−8y
−120
−8 = −8y −8
−120
−8 =1·y 15 =y 34.0.39t=−2.73 0.39t 0.39 =
−2.73
0.39 1·t=
−2.73
0.39 t=−7
36. −
7 6 y=− 7 8 − 6 7 ) − 7 6 c (y)=− 6 7 ) − 7 8 c 1·y= 42 56 y= 3 4 38.4x−7=81 4x=88 x=22 40.6z−7=11 6z=18 z=3 42.5x+7=−108 5x=−115 x=−23
44.−
9 2 y+4=− 91 2 −9y+8=−91 −9y=−99 y=11 46.9 5 y+ 4 10 y= 66 10 18y+4y= 66 Multiplying by 10 22y=66 y=3 48.0.8t−0.3t=6.5 0.5t=6.5 t=13 50.15x+40=8x−9 15x=8x−49 7x=−49 x=−7 52.3x−15=15+3x −15 = 15 False equation No solution 54.9t−4=14+15t 9t−18 = 15t −18 = 6t −3=t 56.6−7x=x−14 20−7x=x 20=8x 20 8 =x 5 2 =x 58.5x−8=−8+3x−x 5x−8=−8+2x 3x=0 x=0 60.6y+20=10+3 y+y 6y+20=10+4 y 2y=−10 y=−5 62.−3t+4=5−3t
- = 5 False equation
- = 5 True equation
No solution 64.5−2y=−2y+5
All real numbers are solutions.
66.3(y+6)=9y 3y+18=9y 18=6y 3=y 68.27 = 9(5y−2) 27 = 45y−18 45 = 45y 1=y 70.210(x−3) = 840 210x−630 = 840 210x= 1470 x=7 72.8x−(3x−5)=40 8x−3x+5=40 5x=35 x=7 Copyrightcf2015 Pearson Education, Inc. 2 / 4
Exercise Set 1.219 74.3(4−2x)=4−(6x−8) 12−6x=4−6x+8 12−6x=12−6x 12 = 12 True equation All real numbers are solutions.
76.−40x+ 45 = 3[7−2(7x−4)] −40x+ 45 = 3[7−14x+8] −40x+45=3[−14x+ 15] −40x+45=−42x+45 2x=0 x=0 78.1 6 (12t+ 48)−20 =− 1 8 (24t−144) 2t+8−20 =−3t+18 5t=30 t=6 80.6[4(8−y)−5(9+3y)]−21 =−7[3(7 + 4y)−4] 6[32−4y−45−15y]−21 =−7[21 + 12y−4] 6[−13−19y]−21 =−7[17 + 12y] −78−114y−21 =−119−84y 20=30y 2 3 =y 82.3 4 ) 3x− 1 2 c + 2 3 = 1 3 54x−9 + 16 = 8 Multiplying by 24 54x=1 x= 1 54 84.9(4x+7)−3(5x−8) = 6 ( 2 3 −x f −5 ( 3 5 +2x f 36x+63−15x+24=4−6x−3−10x 21x+87=−16x+1 37x=−86 x=− 86 37 86.a −9a 23 =a −32 = 1 a 32 88.−2x 8 y 3 90.−5+6x 92.−10x+35y−20 94.4(−x−6y), or−4(x+6y) 96.5(−2x+7y−4), or−5(2x−7y+4)
98.{−8,−7,−6,−5,−4,−3,−2,−1};
{x|xis a negative integer greater than−9} 100.−0.00458y+1.7787 = 13.002y−1.005 −13.00658y=−2.7837 y≈0.214 102.2x−5 6 + 4−7x 8 = 10 + 6x 3 4(2x−5) + 3(4−7x) = 8(10 + 6x) Multiplying by 24 8x−20+12−21x=80+48x −88=61x − 88 61 =x 104.23−2{4+3(x−1)}+5{x−2(x+3)}= 7{x−2[5−(2x+ 3)]} 23−2{4+3x−3}+5{x−2x−6}= 7{x−2[5−2x−3]} 23−2{3x+1}+5{−x−6}= 7{x−2[−2x+2]} 23−6x−2−5x−30 = 7{x+4x−4} −11x−9= 7{5x−4} −11x−9= 35x−28 19=46x 19 46 =x Exercise Set 1.2 RC2.qs+4r=t qs=t−4r q= t−4r s The answer is (b).RC4.4q=7r q= 7r 4 ,or 7 4 r The answer is (a).RC6.7r−t=4s 7r=4s+t r= 4s+t 7 The answer is (e).
2.d=rt d r =t 4.V= 4 3 πr 3 3V 4π =r 3 Copyrightcf2015 Pearson Education, Inc. 3 / 4
20 Chapter 1:Solving Linear Equations and Inequalities
- P=2w+2l
P−2w=2l P−2w 2 =l,or P 2 −w=l 8.A= 1 2 bh 2A=bh 2A b =h
10. A=
a+b 2 2A=a+b 2A−a=b 12.F=ma F m =a 14.I=Prt I rt =P 16.E=mc 2 Ec 2 =m 18.Q= p−q 2 2Q=p−q q=p−2Q 20.Ax+By=c Ax=c−By x= c−By A 22.F= mv
- r
Fr m =v 2 Multiplying by r m
24. N=
1 3 M(t+w) 3N=M(t+w) 3N M =t+w 3N M −t=w,or 3N−Mt M =w
- t=
- g=m+mnp
- Z=Q−Qab
1 6 (x−y+z) 6t=x−y+z 6t−x+y=z
g=m(1 +np) g 1+np =m
Z=Q(1−ab) Z 1−ab =Q 32.a)5 ft 6 in. = 5×12 in. + 6 in. = 66 in.
R=665+4.35(145) + 4.7(66)−4.7(32)≈
1446 calories b)R=655+4.35w+4.7h−4.7a R−655−4.35w+4.7a=4.7h R−655−4.35w+4.7a 4.7 =h 34.a)6 ft 2 in. = 6×12 in. + 2 in. = 74 in.
K= 102.3+9.66(210) + 19.69(74)−10.54(34)≈
3230 calories b)K= 102.3+9.66w+19.69h−10.54a K−102.3−9.66w−19.69h=−10.54a K−102.3−9.66w−19.69h
−10.54
=a,or 102.3+9.66w+19.69h−K 10.54 =a 36.a)P=94.593c+34.227a−2134.616
P=94.593(26.7)+34.227(24.1)−2134.616
P≈1216 g b)P=94.593c+34.227a−
2134.616
P−34.227a+ 2134.616 = 94.593c P−34.227a+ 2134.616
94.593
=c 38.a)F= n 15 F=
42,690
15 F= 2846 students b)F= n 15 15F=n
40.−2000÷(−8) =
−2000
−8 = 250
42.120÷(−4.8) =
120
−4.8
=−25
44.−90 −15 =6 46.−80 16 =−5
48.Solve fora:
s=v 1t+ 1 2 at 2 s−v 1t= 1 2 at 2 2(s−v 1t)=at 2 2(s−v 1t) t 2 =a Copyrightcf2015 Pearson Education, Inc.
- / 4