When adding or subtracting with scientific notation, why is it important to have the same power of 10?

Use the diagonals to determine whether a parallelogram with vertices u(2,−2), v(9,−2), w(9,−6), and x(2,−6) is a rectangle, rhombus, or square. give all the names that apply.

Can you simplify 4/7? 24 points will be awarded!

Someone answer asap 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)) =