Write in standard form 8x2−5+7x4−9x−x5

Please explain i don't understand

If the measure of xyz is 81 what is the measure of yz

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. after tax the total is 45.99. what percentage of the subtotal is the total?

Which type of graph would allow us to compare the median number of teeth for mammals and reptiles easily