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Needing a little bit with this one. -1+|-9+x|=11

1 Answer

3 votes

Answer:

x = - 3 , x = 21

Explanation:

given the absolute value equation

- 1 + |- 9 + x | = 11 ( add 1 to both sides )

| - 9 + x | = 12

the absolute value function , always gives a positive result, however the expression inside the bars can be positive or negative.

there are then 2 equations to be solved

- 9 + x = 12 or - (- 9 + x) = 12

- 9 + x = 12 ( add 9 to both sides )

x = 21

or

- (- 9 + x) = 12 ← distribute parenthesis by - 1

9 - x = 12 ( subtract 9 from both sides )

- x = 3 ( multiply both sides by - 1 )

x = - 3

solutions are x = - 3 , x = 21

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