I need help please 1) George left a 19% tip on a $90 dinner bill. How much was the tip?

Yoku is putting on sunscreen. he uses 2\text{ ml}2 ml to cover 50\text{ cm}^250 cm 2 of his skin. he wants to know how many milliliters of sunscreen (c)(c) he needs to cover 325\text{ cm}^2325 cm 2 of his skin. how many milliliters of sunscreen does yoku need to cover 325 \text{ cm}^2325 cm 2 of his skin?

What are “like terms”? why can we only add like terms?

Solve the equation - 2(m -30) = -6m a-15 b-13 c-8 d8