The price a hat was $20. It is on sale for $15. What is the percent of change in the price of the hat?

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11

In need of in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?