# How do you write an nth term rule for -3,6,-12,24,... and find a_6?

Aug 25, 2016

${t}_{n} = - 3 \times - {2}^{n - 1}$
${a}_{6} = 96$

#### Explanation:

We use the formula ${t}_{n} = a \times {r}^{n - 1}$ when we want to find nth term rules and terms in geometric sequences.

${t}_{n} = a \times {r}^{n - 1}$

${t}_{n} = - 3 \times - {2}^{n - 1}$

That's as far as we can simplify the nth term rule.

We can use this formula to determine ${a}_{6}$.

${t}_{6} = - 3 \times - {2}^{6 - 1}$

${t}_{6} = - 3 \times - {2}^{5}$

${t}_{6} = - 3 \times - 32$

${t}_{6} = 96$

Hopefully this helps!