How do you know if -4^2 is -16 or 16?

Write the pair of fractions as a pair of fractions with a common denominator

The weight v of an object on venus varies directly with its weight e on earth. a person weighing 120 lb on earth would weigh 106 lb on venus. how much would a person weighing 150 lb on earth weigh on venus?

At your job you're paid $50 per week plus $3 per sale at least how many saled do you need to make in order to have over $250