## marigirl one year ago Could you please explain mathematically what actually happens to the absolute value below

1. marigirl

$\ln \left| 2k^3-1 \right|=7.5$

2. marigirl

Then I would go $\left| 2k^3-1 \right|=e^(7.5)$

3. marigirl

what will happen to the absolute function value now?

4. IrishBoy123

try$2k^3−1=\pm e^{7.5}$

5. marigirl

My question was to solve for k which the value is + or - 9.67 how do we 'get rid' of an absolute value function, or how do we balance an absolute value function in an equation Since absolute value function only look at positive values, I am a little confused with your response @IrishBoy123

6. IrishBoy123

let's say |x| = 3, then we can conclude that x = 3 OR x = -3 yes?

7. IrishBoy123

ie, in that example i give, we conclude $x = \pm3$

8. IrishBoy123

so if $$|x|=e^{7.5}$$, you must consider $$x= \pm e^{7.5}$$

9. IrishBoy123

you should get two answers $\sqrt[3]{\frac{1 \pm e^{7.5}}{2}}$

10. marigirl

oh yea it makes sense now, I got k=9.67 and k=-9.66 Thanks heaps! I really appreciate it

11. IrishBoy123

$$\checkmark$$