Question

x=(-23) +22_ _ _ _ (20terms)​

Answer 1

Step-by-step explanation:

x=(-23) +22 _ _ _ _ (20 terms)

Here,

a = - 23;

d = a₂ - a₁ = 22 - (-23) = 22 + 23 = 45;

n = 20

By using sum of first n terms formula,

Sₙ = $\frac{n}{2}[2a + (n - 1)d]$

S₂₀ = $\frac{20}{2}[2(-23) + (20 - 1)(45)]$

S₂₀ = $\frac{\cancel{20}}{\cancel{2}}[-46 + (19 \times 45)]$

S₂₀ = 10[-46 + 855]

S₂₀ = 10[809]

$\huge{\boxed{\pink{\mathsf{S_{20} = 8090}}}}$