Find the sum of all odd integers between 70 and 120

It forms an AP

AP : 71 , 73 , 75 , .................. 119

a = 71

d = 2

= a + (n-1)d

119 = 71 + (n-1)2

n-1 = (119 - 71)/2

n = 24

= n/2 × (a + )

= 24/2 × (71 + 119)

= 12 × 190 = 2280

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i