Here is a rule for working out the area of a rhombus

What is the slope of a line that is perpendicular to y = 3x + 1

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?