How do you solve $| 9 x - 90 | = 0$ $|9x - 90| = 0$ ?

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Answer 1 · 2016-09-21T10:49:49

Only solution is $x = 10$ $x=10$

Note that if $| x = 0 |$ $|x=0|$ , it is either $x = 0$ $x=0$ or $- x = 0$ $-x=0$ . Bot mean $x = 0$ $x=0$

Similarly $| 9 x - 90 | = 0$ $|9x-90|=0$ means that absolute value of $9 x - 90$ $9x-90$ is zero,

it means either $9 x - 90 = 0$ $9x-90=0$ or $- (9 x - 90) = 0$ $-(9x-90)=0$

i.e. either $9 x = 90$ $9x=90$ or $- 9 x + 90 = 0$ $-9x+90=0$

i.e. either $x = \frac{90}{9} = 10$ $x=90/9=10$ or $- 9 x = - 90$ $-9x=-90$ and $x = \frac{- 90}{- 9} = 10$ $x=(-90)/(-9)=10$

Hence the only solution is $x = 10$ $x=10$

How do you solve |9x - 90| = 0|9x−90|=0|9x - 90| = 0?