Question

Solve x3 = 1 over 8.

1 over 2
±1 over 2
1 over 4
±1 over 4

Answer 1

\[x ^{3} = \frac{ 1 }{ 8 }\] Yes?

In this case, "x" is a number that, when multiplied by itself 3 times gives us 1/8; you could also say x*x*x = 1/8
We can try each of the options in turn to see if they work. I'll start from the bottom so as not to give away the answer too quickly:
\[\frac{1}{4} * \frac{1}{4} * \frac{1}{4} = \frac{1}{64}\]
So neither the fourth nor third options would be correct
Now,
\[\frac{1}{2} * \frac{1}{2} * \frac{1}{2} = \frac{1}{8}\]
but
\[-\frac{1}{2} * -\frac{1}{2} * -\frac{1}{2} = -\frac{1}{8}\]
So this would not be correct
Only POSITIVE 1/2 works in this case, NOT NEGATIVE 1/2, since you get a different result for -1/2

I trust that you can see which answer you should choose, yes?

Answer 2

oooh i get it now. but i dont understand this ±

Answer 3

That symbol, ± is the same as saying + AND -
So, ±1/2, for example, would include positive 1/2 and negative 1/2 in the solution; ±1/4 would be the same as saying positive 1/4 and negative 1/4, etc.
You use ± when you want to say both the positive and the negative values of the number

Answer 4

ok

Answer 5

thank you