What numbers multiplied equal to -4 and add up to 8

What is the value of the expression below? (81^2)^1/8

Afruit stand has to decide what to charge for their produce. they need $10 for 4 apples and 4 oranges. they also need $15 for 6 apples and 6 oranges. we put this information into a system of linear equations. can we find a unique price for an apple and an orange?

What is the value of y? round to the nearest tenth