How do you solve abs(x-10)=17|x10|=17?

2 Answers
Apr 24, 2017

x=27,-7x=27,7

Explanation:

With absolute value equations, you need to evaluate both negative and positive circumstances of the absolute value.

|x-10|=17|x10|=17

AND

|x-10|=-17|x10|=17

[We ignore the absolute value sign until we check our answers]

So,

x-10=17x10=17

x=17+10x=17+10

x=27x=27

AND

x-10=-17x10=17

x=-17+10x=17+10

x=-7x=7

Therefore, our two values for xx are 2727 and -77

I'll check them below for reference.
[Remember to substitute your values only into the original equation!]

|x-10|=17|x10|=17

|27-10|=17|2710|=17

|17|=17|17|=17

17=1717=17

OR

|x-10|=17|x10|=17

|-7-10|=17|710|=17

|-17|=17|17|=17

17=1717=17

Apr 24, 2017

x=-7" or " x=27x=7 or x=27

Explanation:

The value inside the color(blue)"absolute value function"absolute value function can be positive or negative. This means there are 2 possible solutions.

|x=10|=17|x=10|=17

rArrx-10=color(red)(+-)17x10=±17

(1)" solve " x-10=color(red)(+)17(1) solve x10=+17

"add 10 to both sides"add 10 to both sides

xcancel(-10)cancel(+10)=17+10

rArrx=27" is a possible solution"

(2)" solve " x-10=color(red)(-)17

"add 10 to both sides"

rArrx=-17+10

rArrx=-7" is a possible solution"

color(blue)"As a check"

Substitute these values into the left side of the equation and if equal to the right side then they are the solutions.

"left side "=|27-10|=|17|=17=" right side"

"left side "=|-7-10|=|-17|=17=" right side"

rArrx=-7" or " x=27" are the solutions"