✔ 最佳答案
14.
x - 6 = (x - 3)/4
Multiply both sides by 4:
4(x - 6) = x - 3
4x - 24 = x - 3
3x = 21
x = 7
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16.
8x + [(3x - 7)/2] = 6
Multiply both sides by 2:
16x + (3x - 7) = 12
16x + 3x - 7 = 12
19x = 19
x = 1
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18.
(x/3) - (x/2) = 1
Multiply both sides by 6:
2x - 3x = 6
-x = 6
x = -6
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20.
(2s/3) - 1 = (s + 2)/5
multiply both sides by 15:
10s - 15 = 3(s + 2)
10s - 15 = 3s + 6
7s = 21
s = 3
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22.
(1/9)(h+9) = (5/6) - (1/2)(h + 7)
Multiple both sides by 18:
2(h + 9) = 15 - 9(h + 7)
2h + 18 = 15 - 9h - 63
11h = -66
h = -6
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4m+(1/3)=1 2/3 - (1/3)m
4m + (1/3) = (5/3) - (1/3)m
Multiply both sides by 3:
12m + 1 = 5 - m
13 m = 4
m = 4/13
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(s + 1)/3 + (s - 1)/7 = -6
Multiply both sides by 21:
7(s + 1) + 3(s - 1) = -126
7s + 7 + 3s - 3 = -126
10s = -130
s = -13
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A sum of $120 is divided between 2 sisters.The elder sister spends 1/5 of the amount received while the younger sister spends 1/6 of the amount received.
If the elder sister spends $13 more than the younger sister,how much does each of them receive?
Let $y be the amount that the eldest sister receives.
The amount that the younger sister receives = $(120 - y)
(y/5) - (120 - y)/6 = 13
Multiply both sides by 30:
6y - 5(120 - y) = 390
6y - 600 + 5y = 390
11y = 990
y = 90
120 - y = 30
The elder sister receives $90, and the younger sister receives $30.
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The number of hours John spends on studying is normally 3 times that of Simon.
This week,each of them spends 6 hours more on studying.As a result, John spends 12 hours more than Simon.How many hours does:
a.John normally spend on studying a week?
b.Simon normally spend on studying a week?
Let 3y hours be the duration that John normally spends on studying a week.
Duration that Simon normally spends on studying a week = y hours
This week John spends (3y + 6) hours on studying,
and Simon spends (y + 6) hours on studying.
(3y + 6) - (y + 6) = 12
3y + 6 - y - 6 = 12
2y = 12
y = 6
3y = 18
(a) Duration that John normally spends on studying a week = 18 hours
(b) Duration that Simon normally spends on studying a week = 6 hours
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