Algebra Demystified 2nd Ed

(Marvins-Underground-K-12) #1
Chapter 7 linear equaTionS 217

4.^6741 xx+− =^3824 xx+− This is in the form “Fraction = Fraction,” so cross-multiply.


() 67 () 24 () 41 () 38
12 2224 14 28 12

xx xx
xxxx

+−=−+
−+−=+ 332 38
12 10 28 12 29 812
10

222

xx
xx xx x

−−
−−=+−

,scancel

xxx
xx
x

x

−= −
++
−= −
++
−=

28 29 8
10 10
28 39 8
88
20 39

− (^20) =
39
x
5.
9
1
3
31
x
3 xx
4

=+
−^ The LCD is 3x − 1.
() ()
()
319
31
314 3
31
931
x x
x
x
x
xx






=−+





=−(()()
431 3
31
91243
9121
99
+−





=−+
=−
−−
x
x
xx
xx
x xx
x
x
x
031
11
13
1
3
=−
++


=
If we let x=^13 , then both denominators would be 0, so x=^13 is not a
solution to the original equation. The original equation has no solution.

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