Begin by grouping the first two terms together and the last two together, then factor and redistribute
(4x^3+x^2)+(-8x-2)
(x^2)(4x+1)+(-2)(4x+1)
x^2(4x+1)-2(4x+1)
the answer is the first one
Standard deviation(σ

) = √V(X) = 10
Therefore, the variance of X, V(X) = 10² = 100
The variance of aX is determined by
V(aX) = a²V(X)
Thus, the variance of 3X becomes
V(3X) = 3²V(X) = 9(100) = 900
Consequently, the standard deviation of 3X is
σ

= √V(3X) = √900 = 30