1. |x2-1|=|x-1|
|x2−1|=|x−1|(x2−1)=(x−1)(x+1)(|(x−1)(x+1)|)2=(|x−1|)2(square both sides)( (x−1)(x+1) )2=(x−1)2( (ab)2=a2b2 )(x−1)2(x+1)2=(x−1)2(x−1)2(x+1)2−(x−1)2=0(x−1)2[(x+1)2−1]=0(x−1)2(x2+2x+1−1)=0(x−1)2(x2+2x)=0(x−1)2⋅x⋅(x+2)=0(x−1)⋅(x−1)⋅x⋅(x+2)=01.x−1=0x=12.x=03.x+2=0x=−2
2. 3|x-2|=2|x-3|
3|x−2|=2|x−3|(3|x−2|)2=(2|x−3|)2(square both sides)32(x−2)2=22(x−3)2( (ab)2=a2b2 )9(x−2)2=4(x−3)29(x2−4x+4)=4(x2−6x+9)9x2−36x+36=4x2−24x+369x2−36x=4x2−24x5x2−12x=0x⋅(5x−12)=01.x=02.5x−12=0x=125
3. |4-x|=5
|4−x|=5(|4−x|)2=(5)2(square both sides)(4−x)2=25(±√)4−x=±5x=4±51.x=4+5x=92.x=4−5x=−1
4. |2x-7|=|x-5|
|2x−7|=|x−5|(|2x−7|)2=(|x−5|)2(square both sides)(2x−7)2=(x−5)24x2−28x+49=x2−10x+253x2−18x+24=0:3x2−6x+8=0(x−4)(x−2)=01.x−4=0x=42.x−2=0x=2
5. |x2-x|=|x2-1|
|x2−x|=|x2−1|x2−x=x(x−1)(x2−1)=(x−1)(x+1)|x(x−1)|=|(x−1)(x+1)|( |x(x−1)| )2=( |(x−1)(x+1)| )2(square both sides)( x(x−1) )2=( (x−1)(x+1) )2( (ab)2=a2b2 )x2(x−1)2=(x−1)2(x+1)2x2(x−1)2−(x−1)2(x+1)2=0(x−1)2[x2−(x+1)2]=0(x−1)2(x2−x2−2x−1)=0(x−1)2(−2x−1)=0(x−1)⋅(x−1)⋅(−2x−1)=01.x−1=0x=12.−2x−1=0x=−12
These are always a little difficult to wrap one's head around.....!!!
They are all solved in pretty much the same manner ....!!!
1. abs (x^2 - 1) = abs (x - 1)
We have two equations that result
x^2 - 1 = x - 1 and x^2 -1 = -(x - 1) working on both, we have
x^2 = x x^2 - 1 = -x + 1
x^2 - x = 0 x^2 + x - 2 = 0
x(x-1) = 0 (x +2) ( x-1) = 0
So x = 0 , 1 So x = -2 and x = 1
The solutions are x = -2, x = 0 and x = 1
Look at the graph of the solutions, here.........https://www.desmos.com/calculator/sanncuv3uw
2. 3|x-2|=2|x-3| divide both sides by 2
(3/2)|x-2|=lx-3| as before, we have.....
(3/2)(x - 2) = x -3 and (3/2)(x - 2) = -(x - 3)
(3/2)lx - 2 l = - x + 3
Multiply through by 2 in both equations.....
3(x -2) = 2x - 6
3x - 6 = 4x - 6 3(x - 2) = -2x + 6
The only solution to this is 3x - 6 = -2x + 6
when x = 0
5x = 12
x = 12/5 = 2 + 2/5 = 2.4
So the two solutions are x = 0 and x = 2.4
See the solution graphs, here..... https://www.desmos.com/calculator/frf6guc36z
3. |4-x|=5 this one is easy
Either
4 - x = 5 or 4 - x = -5
-x = -1 -x = -9
x = 1 x = 9
These solutions are easily verified in the original problem
4 . |2x-7|=|x-5|
2x - 7 = x - 5 or 2x - 7 = -(x - 5)
x = 2 2x - 7 = -x + 5
3x = 12
x = 4
Again......these are easily verified
5. |x^2-x|=|x^2-1| similar to the first one, we have
x^2 - x = x^2 - 1 or x^2 - x = - (x^2 - 1)
-x = -1 x^2 - x = -x^2 + 1
x = 1 2x^2 - x - 1 = 0
(2x +1) ( x - 1) = 0
Set each factor to 0
x = -1/2 [ x = 1 .....a repeated solution]
Here's the graph......https://www.desmos.com/calculator/kcbcpd3khj
1. |x2-1|=|x-1|
|x2−1|=|x−1|(x2−1)=(x−1)(x+1)(|(x−1)(x+1)|)2=(|x−1|)2(square both sides)( (x−1)(x+1) )2=(x−1)2( (ab)2=a2b2 )(x−1)2(x+1)2=(x−1)2(x−1)2(x+1)2−(x−1)2=0(x−1)2[(x+1)2−1]=0(x−1)2(x2+2x+1−1)=0(x−1)2(x2+2x)=0(x−1)2⋅x⋅(x+2)=0(x−1)⋅(x−1)⋅x⋅(x+2)=01.x−1=0x=12.x=03.x+2=0x=−2
2. 3|x-2|=2|x-3|
3|x−2|=2|x−3|(3|x−2|)2=(2|x−3|)2(square both sides)32(x−2)2=22(x−3)2( (ab)2=a2b2 )9(x−2)2=4(x−3)29(x2−4x+4)=4(x2−6x+9)9x2−36x+36=4x2−24x+369x2−36x=4x2−24x5x2−12x=0x⋅(5x−12)=01.x=02.5x−12=0x=125
3. |4-x|=5
|4−x|=5(|4−x|)2=(5)2(square both sides)(4−x)2=25(±√)4−x=±5x=4±51.x=4+5x=92.x=4−5x=−1
4. |2x-7|=|x-5|
|2x−7|=|x−5|(|2x−7|)2=(|x−5|)2(square both sides)(2x−7)2=(x−5)24x2−28x+49=x2−10x+253x2−18x+24=0:3x2−6x+8=0(x−4)(x−2)=01.x−4=0x=42.x−2=0x=2
5. |x2-x|=|x2-1|
|x2−x|=|x2−1|x2−x=x(x−1)(x2−1)=(x−1)(x+1)|x(x−1)|=|(x−1)(x+1)|( |x(x−1)| )2=( |(x−1)(x+1)| )2(square both sides)( x(x−1) )2=( (x−1)(x+1) )2( (ab)2=a2b2 )x2(x−1)2=(x−1)2(x+1)2x2(x−1)2−(x−1)2(x+1)2=0(x−1)2[x2−(x+1)2]=0(x−1)2(x2−x2−2x−1)=0(x−1)2(−2x−1)=0(x−1)⋅(x−1)⋅(−2x−1)=01.x−1=0x=12.−2x−1=0x=−12