Question

the value of 1/2-3/4+5/6-7/8 is​

Answer 1

Answer:

step-by-step explanation :

we have to find the sum of

1+2+3+4+..........................+45

Looking the sequence,

we come to know that,

we have to find the sum of first 45 natural numbers.

Now,

we know that,

sum of n natural numbers = n(n+1)/2

Here,

n = 45

putting the value of n= 45 in the abive formula,

we get,

sum = 45 × (45+1)/2

= 45 × 46/2

= 45 × 23

= 1035

Hence,

1+2+3+4+............+45 = 1035

Answer 2

Answer:

47/24

Step-by-step explanation:

First we find l.c.m of 2 and 4

2 × 2 = 4

now we multiply 1/2 from 2 so, answer will be 2/4

then we again multiply 3/4 from 1 so, this answer will be 3/4

now we subtract 3/4 - 2/4

3/4 - 2/4 = 1/4

now we again find l.c.m of 4 and 6

2 × 2 × 3 = 12

now we multiply 1/4 from 3 so, answer with be 3/12

now we again multiply 5/6 from 2 so, answer will be 10/12

now we add 3/12 + 10/12

3/12 + 10/12 = 13/12

now we again find l.c.m of 8 and 12

2 × 2 × 2 × 3 = 24

now we multiply 13/12 from 2 so, answer will will be 26/24

now we again multiply 7/8 from 3 so answer will be 21/24

now we add 26/24 + 21/24

26/24 + 21/24 = 47/24