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3 votes
| x - 1 | = 5x + 10
Check for extraneous solutions.

2 Answers

4 votes
Solution #1
x-1=5x+10


x-1=5x+10


x-5x=10+1


-4x=11


x=-11/4

Solution #2
x-1=-(5x+10)


x-1=-(5x+10)


x-1=-5x-10


x+5x=-10+1


6x=-9


x=-9/6=-3/2

We have two possible outcomes.
User Glen Elkins
by
8.1k points
6 votes
[x-1]=5x+10

We have two equations:
1) x-1=5x+10

x-1=5x+10
x-5x=10+1
-4x=11
x=-11/4

2) x-1=-(5x+10)

x-1=-(5x+10)
x-1=-5x-10
x+5x=-10+1
6x=-9
x=-9/6=-3/2

we have two possible solutions:
solution₁; x=-11/4
solution₂: x=-3/2

we check it out:
1) x=-11/4
[x-1]=5x+10
[-11/4 - 1]=5(-11/4)+10
[(-11-4)/4]=-55/4 + 10
[-15/4]=(-55+40) /4
15/4≠-15/4 This solution don´t work.

2) x=-3/2
[x-1]=5x+10
[-3/2 - 1]=5(-3/2)+10
[(-3-2)/2]=-15/2 + 10
[-5/2]=(-15+20)/2
5/2=5/2; this solution works.

Therefore:

Answer: x=-3/2.
User ROROROOROROR
by
7.8k points