Solve for x
4|x| + |2x -2| = |3x -3|
ans: 1/5 and - 1/3
4|x| + |2x -2| = |3x -3|
ans: 1/5 and - 1/3
-
_______________________
4|x| + |2x -2| = |3x -3|
|4x| + 2|x -1| = 3|x -1|
|4x| = 3|x -1| - 2|x -1|
|4x| = |x -1| ← This is true only if 4x and x-1
are equal or opposites
So,
4x = x-1 OR 4x = -(x-1)
3x = -1 4x = 1-x
x = -⅓ x = ⅕
ANSWER
x = -⅓, ⅕
Have a good one!!
____________________________
4|x| + |2x -2| = |3x -3|
|4x| + 2|x -1| = 3|x -1|
|4x| = 3|x -1| - 2|x -1|
|4x| = |x -1| ← This is true only if 4x and x-1
are equal or opposites
So,
4x = x-1 OR 4x = -(x-1)
3x = -1 4x = 1-x
x = -⅓ x = ⅕
ANSWER
x = -⅓, ⅕
Have a good one!!
____________________________
-
Hello,
4|x| + |2x - 2| = |3x - 3|
► To answer any modulus equation you have to find the root of every single modulus expression:
|x|=0 → x=0
|2x-2| = 0 → x=1
|3x-3| = 0 → x=1
Thus there are three intervals to consider: ]-∞; 0], [0; 1] and [1; + ∞[.
We will study them one after the other.
► On interval ]-∞; 0]:
|x| = -x
|2x - 2| = 2 - 2x
|3x - 3| = 3 - 3x
Thus we get:
4|x| + |2x - 2| = |3x - 3|
-4x + 2 - 2x = 3 - 3x
-4x = 1 - x
3x = -1
x = -⅓
Since -⅓ is actually in interval ]-∞; 0], x=-⅓ is really a solution of the equation.
► On interval [0; 1]:
|x| = x
|2x - 2| = 2 - 2x
|3x - 3| = 3 - 3x
Thus we get:
4|x| + |2x - 2| = |3x - 3|
4x + 2 - 2x = 3 - 3x
5x = 1
x = 1/5
Since 1/5 is actually in interval [0; 1], x=1/5 is really a solution of the equation.
► On interval [1; +∞[:
|x| = x
|2x - 2| = 2x - 2
|3x - 3| = 3x - 3
Thus we get:
4|x| + |2x - 2| = |3x - 3|
4x + 2x - 2 = 3x - 3
3x = -1
x = -⅓
Since -⅓ is actually NOT in interval [0; +∞[, x=-⅓ would not be solution of the equation.
However, since the exact same value is solution elsewhere, we can conclude:
► The only real solutions of the modulus equation are
4|x| + |2x - 2| = |3x - 3|
► To answer any modulus equation you have to find the root of every single modulus expression:
|x|=0 → x=0
|2x-2| = 0 → x=1
|3x-3| = 0 → x=1
Thus there are three intervals to consider: ]-∞; 0], [0; 1] and [1; + ∞[.
We will study them one after the other.
► On interval ]-∞; 0]:
|x| = -x
|2x - 2| = 2 - 2x
|3x - 3| = 3 - 3x
Thus we get:
4|x| + |2x - 2| = |3x - 3|
-4x + 2 - 2x = 3 - 3x
-4x = 1 - x
3x = -1
x = -⅓
Since -⅓ is actually in interval ]-∞; 0], x=-⅓ is really a solution of the equation.
► On interval [0; 1]:
|x| = x
|2x - 2| = 2 - 2x
|3x - 3| = 3 - 3x
Thus we get:
4|x| + |2x - 2| = |3x - 3|
4x + 2 - 2x = 3 - 3x
5x = 1
x = 1/5
Since 1/5 is actually in interval [0; 1], x=1/5 is really a solution of the equation.
► On interval [1; +∞[:
|x| = x
|2x - 2| = 2x - 2
|3x - 3| = 3x - 3
Thus we get:
4|x| + |2x - 2| = |3x - 3|
4x + 2x - 2 = 3x - 3
3x = -1
x = -⅓
Since -⅓ is actually NOT in interval [0; +∞[, x=-⅓ would not be solution of the equation.
However, since the exact same value is solution elsewhere, we can conclude:
► The only real solutions of the modulus equation are
12
keywords: modulus,to,qestion,How,this,do,How to do this modulus qestion