Acertain element has a half life of 4.5 billion years. a. you find a rock containing a mixture of the element and lead. you determine that 60% of the original element remains; the other 40% decayed into lead. how old is the rock? b. analysis of another rock shows that it contains 5% of its original element; the other 95% decayed into lead. how old is the rock?

Every rhombus is a square. true false

What is the equation of a line passing through the point (6,1) and parallel to the line whose equation 3x=2y+4

Someone answer this asap rn for ! a discount store’s prices are 25% lower than department store prices. the function c(x) = 0.75x can be used to determine the cost c, in dollars, of an item, where x is the department store price, in dollars. if the item has not sold in one month, the discount store takes an additional 20% off the discounted price and an additional $5 off the total purchase. the function d(y) = 0.80y - 5 can be used to find d, the cost, in dollars, of an item that has not been sold for a month, where y is the discount store price, in dollars. create a function d(c(x)) that represents the final price of an item when a costumer buys an item that has been in the discount store for a month. d(c(x)) =