Wall Street Numbers

92. 7r/12 = -14
7r = -14 x 12
7r = -158
r = -158/7
r = -24

94. 1/3s + 7/9 = 4/3s
7/9 = 4/3s – 1/3s
7/9 = (4-1)/3s
7/9 = 3/3s
7/9 = s

78. v – 4(4-v) = 2(2v – 1)
v – 16 +4v = 4v – 2
-16 + 2 = 4v – 4v – v
-14 = -v
v = 14

86. 9 – 2m/7 = 19
9 – 19 = 2m/7
-10 = 2m/7
-10 x 7 = 2m
-70 = 2m
-70/2 = m
-35 = m

90. 3(x-0.87) = 2x – 4.98
3x – 2.61 = 2x – 4.98
3x – 2x = -4.98 + 2.61
x = 2.37

14. x/2 – x/3 = 5
Taking LCM,
3x/6 – 2x/6 = 5
(3x-2x)/6 = 5
x/6 = 5
x = 30

22. 1/15k + 5 = 1/6k – 10
1/15k – 1/6k = -10 -5
Taking LCM on left hand side,
2/30k – 5/30k = -15
(2-5)/30k = -15
-3/30k = -15
-1/10k = -15
-k = -15 x 10
-k = -150
k = 150

32. 0.5b – 3.4 = 0.2b – 12.4
0.5b – 0.2b = -12.4 + 3.4
0.3b = 9.0
Multiplying both sides by 10
0.3b x 10 = 9.0 x 10
3b = 90
b = 90/3
b = 30

54. - 6x + 3 = -7 - 5x
-6x + 5x = -7 – 3
-x = -10
x = 10
68. 3 – 3(5-x) = 0
3 – 15 + 3x = 0
-12 + 3x = 0
3x = 12
x = 12/3
x = 4

32.   x – a = -x + a + 4b
x + x = a + 4b + a
2x = 2a + 4b
x = (2a + 4b)/2
x = a + 2b

54. y + ½ = -1/3(x+1/2)
y + ½ = -x/3 -1/6
y = -x/3 -1/6-1/2
Taking LCM on right side,
y = -2x/6 – 1/6 – 3/6
y = (-2x – 1 – 3)/6
y = (-2x – 4)/6
y = (-x -2)/3

72. S = n(n + 1)(2n + 1)/6
N S
1 1
2 5
3 14
4 30
5 55

82. Let MSRP of Hummer H1 be x.
Discount = 8 %
Discount amount = 8 % or x = $ (8/100)x = $0.08x
Selling price = $ 107272
We know that,
MSRP = Selling price + Discount amount
x = 107272 + 0.08x
x – 0.08x = 107272
0.92x = 107272
x = 116600
Therefore, MSRP = $116,600