Write an expression with (-1) as its base that will produce a positive, and explain why your answer is valid ?

cheap answer, recall that minus * minus = plus. So if we just use any even exponent for (-1), that'll give us a positive.

(-1)² = (-1)(-1) = +1

(-1)⁴ = (-1)(-1)(-1)(-1) = 1

(-1)¹⁰ = (-1)(-1)(-1)(-1)(-1)(-1)(-1)(-1)(-1)(-1) = 1.

what i would say the best answer is a. 40.5