Answer 1

−37, −33, −29 ,…, to 12 terms

For this A.P.,

a = −37

d = a₂ − a₁ = (−33) − (−37)

= − 33 + 37 = 4

n = 12

We know that,

S_n = `n/2 [2a + (n - 1) d]`

S₁₂ = `12/2 [2(-37) + (12 - 1) × 4]`

= 6[-74 + 11 × 4]

= 6[-74 + 44]

= 6(-30) = -180