OpenStudy (anonymous):

What is the 43rd term of an arithmetic sequence with a rate of increase of -6 and a11 = 12? HELP ME PLEASE

3 years ago
OpenStudy (solomonzelman):

it is called, common ratio, not rate of increase (but whatever...) Fast way to do it, without finding $$\large\color{black}{ a_1}$$. $$\large\color{black}{ a_{43}=a_{11}\times r^{43-11}}$$

3 years ago
OpenStudy (solomonzelman):

plug in your values and solve. IF you have any questions, don't hesitate to ask.

3 years ago
OpenStudy (anonymous):

idk how

3 years ago
OpenStudy (solomonzelman):

ohh, yeah it is arithmetic... -:(

3 years ago
OpenStudy (solomonzelman):

$$\large\color{black}{ a_{43}=a_{11}+ n(43-11)}$$ like this.

3 years ago
OpenStudy (anonymous):

what do i put in for a

3 years ago
OpenStudy (solomonzelman):

$$\large\color{black}{ a_{43}=a_{11}+ n(43-11)}$$ $$\large\color{black}{ a_{43}=12+(-6)(43-11)}$$ $$\large\color{black}{ a_{43}=?}$$

3 years ago
OpenStudy (anonymous):

-180

3 years ago