Question

What is 1+2+3+4+5+6+7+8+9=?

Answer 1

Answer:

45

Easy way:

1+9=10

2+8=10

3+7=10

4+6=10

5=5

10+10+10+10+5=45

Answer 2

Answer:

Hence we get the value of  1+2+3+4+5+6+7+8+9$=45$

Step-by-step explanation:

In accordance with the information provided in the question,

We have find the value of the supplied expression in the above question.

Given the data in question  1+2+3+4+5+6+7+8+9

Where numbers starts from 1 and ends on 9

So total number of terms will be 9

As we know that

Sum of n natural number can be determined by using formula,

$sum=\frac{n(n+1)}{2}$

Where n = 9 ( number of terms)

So after putting the value of n we will get the sum as,

$sum =\frac{9\times(9+1)}{2} \\sum=\frac{9\times10}{2} \\sum=9\times 5\\sum=45$