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8/9(54x−36)+2=−3/4(−40+16x)+90x

 Sep 13, 2016
 #1
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Solve for x:
2+(8 (54 x-36))/(9) = 90 x-(3 (16 x-40))/(4)

Put each term in 2+(8 (54 x-36))/9 over the common denominator 9: 2+(8 (54 x-36))/9 = 18/9+(8 (54 x-36))/9:
18/9+(8 (54 x-36))/9 = 90 x-(3 (16 x-40))/4

18/9+(8 (54 x-36))/9 = (18+8 (54 x-36))/9:
(18+8 (54 x-36))/9 = 90 x-(3 (16 x-40))/4

8 (54 x-36) = 432 x-288:
(432 x-288+18)/9 = 90 x-(3 (16 x-40))/4

Grouping like terms, 432 x-288+18 = 432 x+(18-288):
(432 x+(18-288))/9 = 90 x-(3 (16 x-40))/4

18-288 = -270:
(432 x+-270)/9 = 90 x-(3 (16 x-40))/4

Put each term in 90 x-(3 (16 x-40))/4 over the common denominator 4: 90 x-(3 (16 x-40))/4 = (360 x)/4-(3 (16 x-40))/4:
(432 x-270)/9 = (360 x)/4-(3 (16 x-40))/4

(360 x)/4-(3 (16 x-40))/4 = (360 x-3 (16 x-40))/4:
(432 x-270)/9 = (360 x-3 (16 x-40))/4

-3 (16 x-40) = 120-48 x:
(432 x-270)/9 = (360 x+120-48 x)/4

Grouping like terms, 360 x-48 x+120 = (360 x-48 x)+120:
(432 x-270)/9 = ((360 x-48 x)+120)/4

360 x-48 x = 312 x:
(432 x-270)/9 = (312 x+120)/4

Multiply both sides by 36:
(36 (432 x-270))/9 = (36 (312 x+120))/4

36/9 = (9×4)/9 = 4:
4 (432 x-270) = (36 (312 x+120))/4

36/4 = (4×9)/4 = 9:
4 (432 x-270) = 9 (312 x+120)

Expand out terms of the left hand side:
1728 x-1080 = 9 (312 x+120)

Expand out terms of the right hand side:
1728 x-1080 = 2808 x+1080

Subtract 2808 x from both sides:
(1728 x-2808 x)-1080 = (2808 x-2808 x)+1080

1728 x-2808 x = -1080 x:
-1080 x-1080 = (2808 x-2808 x)+1080

2808 x-2808 x = 0:
-1080 x-1080 = 1080

Add 1080 to both sides:
(1080-1080)-1080 x = 1080+1080

1080-1080 = 0:
-1080 x = 1080+1080

1080+1080 = 2160:
-1080 x = 2160

Divide both sides of -1080 x = 2160 by -1080:
(-1080 x)/(-1080) = 2160/(-1080)

(-1080)/(-1080) = 1:
x = 2160/(-1080)

The gcd of 2160 and -1080 is 1080, so 2160/(-1080) = (1080×2)/(1080 (-1)) = 1080/1080×2/(-1) = 2/(-1):
x = 2/(-1)

Multiply numerator and denominator of 2/(-1) by -1:
Answer: |x = -2

 Sep 13, 2016
 #2
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8/9(54x−36)+2=−3/4(−40+16x)+90x     distribute the two fractions over the terms in parentheses

 

48x - 32 + 2 = 30 - 12x + 90x       combine like terms

 

48x - 30  = 30 + 78x        ad 30 to both sides......subtract 78x from both sides

 

-30x  = 60      divide both sides by -30

 

x = -2 

 

 

cool cool cool

 Sep 13, 2016

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