## anonymous one year ago Whats the sum of the first 50 terms? $$\huge { 12 - -\frac{7}{10}n }$$ I am getting \ ( \huge -\frac{445}{2} \) is that right because it is stating it is wrong. They stat it is $$\huge -\frac{585}{2}$$ I am using $$\huge \frac{n}{2}[2*a_1 + (n-1)d) ] to solve$$

1. anonymous

Whats the sum of the first 50 terms? $$\huge { 12 - -\frac{7}{10}n }$$ I am getting \ ( \huge -\frac{445}{2} \) is that right because it is stating it is wrong. They stat it is $$\huge -\frac{585}{2}$$ I am using $$\huge \frac{n}{2}[2*a_1 + (n-1)d) ]$$ to solve

2. anonymous

$$\huge \frac{50}{2}[2*\frac{127}{10} + (50-1)*-\frac{7}{10} ]$$

3. anonymous

This $$\huge \huge { 12 - -\frac{7}{10}n }$$ SHOULD BE $$\huge\huge { 12 - \frac{7}{10}n }$$

4. anonymous

Wait, so is the sequence $$a_n=12-\frac{7}{10}n$$, $$n>0$$?

5. anonymous

Yes

6. anonymous

Ok, if so, I think what you did wrong is that your first term is wrong.$a_1=12-\frac{7}{10}=\frac{113}{10}$

7. anonymous

Ah and I got 127/10. Now how did I get 127...... That was the problem.... I hate mis calculating problems lol Thank you. It came up to be correct.

8. anonymous

lol np. Everyone makes these kinds of mistakes from time to time. :)