Find the real or imaginary solutions of each equation by factoring.
81^3-192=0

Question

Find the real or imaginary solutions of each equation by factoring.
81^3-192=0

anonymous · Answer

@hartnn how do I get rid of the 81?

solomonzelman · Answer

I messed up... it's not clear what the problem actually is -:(

Is it
$$81x^3=192~~~?$$

solomonzelman · Answer

$$81x^3-192=0~~~~~~~~~~~~~~~\frak   rig ht~?$$

anonymous · Answer

It's the second one you posted.

solomonzelman · Answer

Well, they are the same:) the first one ---> is when I subtract 192 from both sides in the second one.

Anyway,
$$81x^3-192=0$$add 192 to both sides$$81x^3=192$$$$3 \times 27x^3=3 \times 64$$$$27x^3=64$$$$3^{3}x^3=4^{3}$$$$(3x)^3=4^{3}$$can you finish the problem from here ?

solomonzelman · Answer

the first phrase, "add" not "subtract" ....

anonymous · Answer

Where did you get 64?

solomonzelman · Answer

In my process I re-wrote 192 as  64×3   (  and  rewrote 81, as  27×3)

solomonzelman · Answer

I didn't get that

I got$$27x^{3}$$and then re-wrote 27 as 3³