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2007-07-08 06:04:04 · 3 answers · asked by Anonymous in Science & Mathematics Mathematics

3 answers

√(x-1) = x - 3

square both sides

x - 1 = (x - 3)²
x - 1 = x² - 6x + 9
0 = x² - 7x + 10
0 = (x-5)(x-2)
x = 5 or x = 2

but check, since squaring both sides can introduce extraneous solutions.

√(5-1) = √4 = 2 = 5 - 3 ....... OK
√(2-1) = √1 = 1 <> -1 = 2 - 3 .... not OK

so x = 5.

2007-07-08 06:13:36 · answer #1 · answered by Philo 7 · 1 2

sqrt(x-1)=x-3
or,x-1=(x-3)^2 [squaring both sides]
or,x-1=x^2-6x+9
or,x^2-6x+9-x+1=0
or,x^2-7x+10=0
or(x-2)(x-5)=0
therefore,either x-2=0 or x-5=0
If x-2=0,then x=2
If x-5=0,then x=5
or,x=2 or 5 ans

2007-07-08 13:12:42 · answer #2 · answered by alpha 7 · 1 4

square both sides:
x-1=x^2-6x+9
x^2-7x+10=0
x=2,5 answer

2007-07-08 13:11:52 · answer #3 · answered by Anonymous · 1 4

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