Answer:
x = 9 Or x = -9
Step-by-step explanation:
The lines on the side mean that the number is it’s ‘absolute value’.
This means whatever number it is, it is positive.
For example if the number was -2, it would be 2.
Knowing this, the number inside can be positive or negative.
Now since we know, we can solve the equation:
(Slashes show the lines meaning absolute value)
/9x/ = 81
divide each side by 9 so the x is alone:
/9x/÷9 = 81÷9
/x/ = 9
x = 9
Or
x = -9
We can check by substituting the 9 in:
/9·9/ = 81
/81/ = 81
81 = 81
or
/9·(-9)/ = 81
/-81/ = 81
81 = 81
