What is the sum of the finite arithmetic series (-5)+0+5+10+ +65 a. 900 b. 455 c. 450 d. 445

If you want to solve this problem using formulas, there are two important formulas:

t1  =  first term  =  -5          

tn  =  nth term  =  last term  =  -5

n  =  numbr of terms

Sn  =  sum of the n terms

tn  =  t1 + (n - 1)d     --->     65  =  -5 + (n - 1)(5)

                                          65  =  -5 + 5n - 5

                                          65  =  -10 + 5n

                                          75  =  5n

                                            n  =  15

Sn  =  n(t1 + tn)/2     --->     Sn  =  15(-5 + 65)/2

                                          Sn  =  450

So ur answer rounds up to 450

Letter c

:)

hope i helped 

~Luis

answer: solve 5\cdot 2^x=2405⋅2  

x

=2405, dot, 2, start superscript, x, end superscript, equals, 240.

solution

to solve for xxx, we must first isolate the exponential part. to do this, divide both sides by 555 as shown below. we do not multiply the 555 and the 222 as this goes against the order of operations!

\begin{aligned} 5\cdot 2^x& =240 2^x& =48 \\ \end{aligned}  

5⋅2  

x

2  

x

​    

=240

=48

​

step-by-step explanation: