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HELP MATH 100 POINTS HELP US

HELP MATH 100 POINTS HELP US-example-1
User Matthew Abrman
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2 Answers

24 votes
24 votes

Let's solve


\\ \rm\rightarrowtail √(2x-1)-x+2=0


\\ \rm\rightarrowtail √(2x-1)=x-2


\\ \rm\rightarrowtail 2x-1=(x-2)^2


\\ \rm\rightarrowtail 2x-1=x^2-4x+4


\\ \rm\rightarrowtail x^2-6x+5=0


\\ \rm\rightarrowtail (x-1)(x-5)=0

  • x=1 or 2

Option B is correct

As putting 1 as x

  • √1-1+2≠0

User Jdonmoyer
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3.1k points
16 votes
16 votes

Question↷

Which statement best reflects the solution(s) of the equation?


\small √(2x - 1) - x + 2 = 0

Answer↷

There is only one solution: x = 5 .

The solution x = 1 is an extraneous solution.

Solution↷


\small √(2x - 1) - x + 2 = 0

  • Taking (-x+2) to the other side


\small √(2x - 1) = x - 2

  • squaring both of the sides


\small 2x - 1 = {(x - 2 )}^(2)

  • expanding the sqared binomial as ㅤㅤㅤㅤ(a-b)²= a²- 2ab + b²


\small 2x - 1 = {x}^(2) - 2 * x * 2 + {2}^(2)

  • simplifying the equation


\small 2x - 1 = {x}^(2) - 4x + 4

  • asiding the equation


\small {x}^(2) - 4x - 2x + 4 + 1 = 0\:


\small {x}^(2) - 6x + 5 = 0\:

  • using splitting middle term method


\small {x}^(2) - 5x - x+ 5 = 0\:


\small x(x- 5) - (x - 5 )= 0\:


\small (x- 1)(x - 5 )

so the root would either be 5 or 1

_____________________________________

putting the value of x as 1,


\small √(2 * 1 - 1) - 1 + 2 = 0


\small 1 - 1 + 2 = 0


\small 3 - 1≠ 0

hence , it's not the true solution of the equation

_____________________________________

putting the value of x as 5,


\small √(2 * 5 - 1) - 5 + 2 = 0


\small 3 - 5 + 2 = 0


\small 5 - 5 = 0


\small 0 = 0

hence ,it's the true solution of the equation

User Ji Wei
by
3.0k points