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Solve for x in the following equation: |x + 2| − 3 = 0.5x + 1.

User Janks
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1 Answer

6 votes

Answer:

x = 8

Explanation:

In order to solve the equation, you have to apply the definition of absolute value function, which is:

|f(x)| = f(x) if f(x ) ≥ 0

|f(x)| = -f(x) if f(x) < 0

Then you have to solve the equation for both cases.

In this case, f(x) = x+2

-For x+2 ≥ 0 which is equivalent to x ≥ -2

x+2-3 = 0.5x+1

Subtracting 0.5x both sides:

x - 0.5x -3 = 0.5x - 0.5x +1

0.5x -3 = 1

Adding 3 both sides:

0.5x -3 +3 = 1 +3

0.5x = 4

Dividing by 0.5

x = 4/0.5

x = 8. This is a solution because x ≥ -2

- For x+2<0 which is equivalent to x < -2 then |x + 2| = -(x+2)

-(x-2) -3 = 0.5x +1

Applying the distributive property:

-x+2-3=0.5x+1

-x-1=0.5x+1

Adding 1 both sides:

-x =0.5x +2

Subtracting 0.5x both sides:

-x-0.5x = 2

-1.5x =2

Dividing by -1.5

x = - 4/3. But x > -2 therefore is not a solution.

User Webnoob
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