Question

Write each of the following expressions without using absolute value. |z−6|−|z−5|, if z<5

Answer 1

Answer: 6 - 5

Step-by-step explanation:

|z - 6| - |z - 5|    ; z < 5

Since z < 5, then

|z - 6| will be the absolute value of a negative number. Replace the absolute value with a negative and parentheses:

-(z - 6) =  -z + 6

|z - 5| will be the absolute value of a negative number. Replace the absolute value with a negative and parentheses:  

-(z - 5) = -z + 5

Now subtract them without the absolute value signs:

-z + 6 - (-z + 5)

Distribute the negative sign:

-z + 6 + z - 5

-z + z = 0 which leaves:

6 - 5

Answer 2

Answer: 1

Step-by-step explanation: first you need to pretend that the absolute value bars are parentheses. Then substitute a with any number less that five, for example z=3

Now we can write our new equation: (3-6)-(3-5)

now we have to determine if the final answer inside the parentheses is positive or negative. In the first parentheses 3-6=-3 with is negative. In our second parentheses we have 3-5=-2 which is a also negative.

Knowing that both parentheses are negative results we can set up an equation using z instead of 3:

-(z-6)-(-(z-5)) is our new equation. If we simplify this equation we get 1 for an answer