Question

What is the 32nd term of the arithmetic sequence where a1 = 12 and a13 = -60?

Answer 1

now you need to find difference fist. do you know how? :)

Answer 2

no please help?

Answer 3

ok ... the formula is :
\[\LARGE a_{n}=a_1+(n-1)d\]
in this case you have to use:
\[\LARGE a_{13}=12+(13-1)d\]
\[\LARGE -60=12+12d\]
\[\LARGE -60-12=12d\]
\[\LARGE -72=12d\]
\[\LARGE d=-\frac{72}{12}\]
\[\LARGE d=-6\]
so just substitute now:
\[\LARGE a_{n}=a_1+(n-1)d\]
\[\LARGE a_{32}=12+[(32-1)\cdot (-6)]\]
can you do it now ? :)

Answer 4

is it -174?

Answer 5

thanks

Answer 6

\[\LARGE a_{32}=12+(-6\cdot 31 )\]
\[\LARGE a_{32}=12-186\]
\[\LARGE a_{32}=-174\]
yes that's correct. Well done :)
...And , Glad to help :)