Answered

Makakuha ng kaugnay na sagot sa lahat ng iyong katanungan sa IDNStudy.com. Ang aming platform ng tanong at sagot ay idinisenyo upang magbigay ng mabilis at eksaktong sagot sa lahat ng iyong mga tanong.

how many consecutive integers, beginning with 10, must be taken for their sum to equal 2035?



Sagot :

[tex]S_n= \frac{n}{2}[(2a_1+(n-1)d][/tex]

n = ?                    (number of terms)
[tex]a_1 = 10[/tex]         (the first term)
[tex]S_n = 2035[/tex]     (their sum)
[tex]d = 1[/tex]        (common difference of 1 since they are 'consecutive' integers)

[tex]2035= \frac{n}{2}[(2(10)+(n-1)1] \\ \\ 4070= n[20+n-1] \\ \\ 4070=n[19+n] \\ \\ 4070=19n+n^2 \\ \\ n^2+19n-4070= 0 \\ \\ (n+74)(n-55)=0 \\ \\ n=-74\ ;\ \boxed{n=55}[/tex]