Find such numbers from 1 to 288 natural numbers. So that the sum of a small number is equal to the sum of a large number.
Answers
Answer:
Step-by-step explanation:Let the number be n.
So:
1+2+3................n-1 = n+1+n+2......................288
In the first AP,
Sn=n/2*[2a+(n-1)d]
no. of terms=n-1
a=1
d=1
Sn=(n-1)/2*[2+n-1-1]
=(n-1)/2*[n]................(1)
Second AP
a=n+1
d=1
no. of terms=288-n
Sn=n/2*[2a+(n-1)d]
Sn=(288-n)/2*[2+288-n-1]
=(288-n)/2*[n+289]..............(2)
(1)=(2)
So:
(n-1)/2*[n]=(288-n)/2*[n+289]
Multiplying both sides by 2.
==) n(n-1)=(288-n)(289+n)
==)n²-n=83232+288n-289n-n²
==)2n²-n=83232-n
==)2n²=83232
==)n²=83232/2
==)n²=41616
==)n=204
n cannot be negative so n is not -204
The term hence is 204
Hope it helps you.
Thanks
And please mark it as the brainliest.
We can put what Gauss discovered into an easy-to-use formula, which is: (n / 2)(first number + last number) = sum, where n is the number of integers.
We seek n∈{1,…,288} for which
1+2+3+⋯+(n−1)=(n+1)+(n+2)+(n+3)+⋯+288,
or for which
2(1+2+3+⋯+(n−1))+n=1+2+3+⋯+288.
Thus,
n2=n(n−1)+n=12⋅288⋅289=122⋅172 ,
implying n=12⋅17=204. ■