Question

By taking how many terms the sum of given AP will be three thousands seven hundred fourty (3740) 7,14,21,...

Answer 1

Answer:

Step-by-step explanation:

Sn=3740

Here a=7d=7 to find n

Sn=n/2{2a+(n-1)d}

3740=n/2{14+7n-7}

3740×2=n(7n+7)

7480=7n^2+7n

7n^2+7n-7480=0

Comparing the equation with an^2+bn+c=0

a=7 b=7 c=(-7480)

b^2-4ac=7^2-4×7×(-7480)

=209489

n= -b+/-(b^2-4ac)/2a

=-7+/-√(209489)/2×7

= -7+/-458/14

n= -7+458/14 OR n=-7-458/14

= 451/14 = -465/14

Answer cannot be determined