Respuesta :
Answer:
x = 1
Step-by-step explanation:
Given
- | x + 2 | + 1 = 4x - 6 ( subtract 1 from both sides )
- | x + 2 | = 4x - 7 ( multiply both sides by - 1 )
| x + 2 | = - 4x + 7
The absolute value always returns a positive value, but the expression inside can be positive or negative, thus
x + 2 = - 4x + 7 ( add 4x to both sides )
5x + 2 = 7 ( subtract 2 from both sides )
5x = 5 ( divide both sides by 5 )
x = 1
OR
- (x + 2) = - 4x + 7, that is
- x - 2 = - 4x + 7 ( add 4x to both sides )
3x - 2 = 7 ( add 2 to both sides )
3x = 9 ( divide both sides by 3 )
x = 3
As a check substitute these values into both sides of the equation and if both sides are equal then they are the solutions.
x = 1 : - |1 + 2| + 1 = - | 3 | + 1 = - 3 + 1 = - 2
right side = 4(1) - 6 = 4 - 6 = - 2 ← True
x = 3 : - |3 + 2| + 1 = - |5| + 1 = - 5 + 1 = - 4
right side = 4(3) - 6 = 12 - 6 = 6 ← False
Thus x = 3 is an extraneous solution and
x = 1 is the solution
Answer:
x = 1
Step-by-step explanation:
[tex]|a|=\left\{\begin{array}{ccc}a&for&a\geq0\\-a&for&a<0\end{array}\right\\\\|x+2|=\left\{\begin{array}{ccc}x+2&for&x+2\geq0\to x\geq-2\\-(x+2)&for&x<-2\end{array}\right[/tex]
[tex](1)\ x<-2\\\\-\bigg(-(x+2)\bigg)+1=4x-6\\\\+(x+2)+1=4x-6\qquad\text{combine like terms}\\\\x+(2+1)=4x-6\\\\x+3=4x-6\qquad\text{subtract 3 from both sides}\\\\x+3-3=4x-6-3\\\\x=4x-9\qquad\text{subtract}\ 4x\ \text{from both sides}\\\\x-4x=4x-4x-9\\\\-3x=-9\qquad\text{divide both sides by (-3)}\\\\\dfrac{-3x}{-3}=\dfrac{-9}{-3}\\\\x=3\notin(1)[/tex]
[tex](2)\ x\geq-2\\\\-(x+2)+1=4x-6\\\\-x-2+1=4x-6\\\\-x+(-2+1)=4x-6\\\\-x-1=4x-6\qquad\text{add 1 to both sides}\\\\-x-1+1=4x-6+1\\\\-x=4x-5\qquad\text{subtract}\ 4x\ \text{from both sides}\\\\-x-4x=4x-4x-5\\\\-5x=-5\qquad\text{divide both sides by (-5)}\\\\\dfrac{-5x}{-5}=\dfrac{-5}{-5}\\\\x=1\in(2)[/tex]