PLEASE HELP PLEASE OMG HELP

WHICH OF THESE COULD BE A STEP TO PROVE THAT BC^2 = AB^2 + AC^2?

Answer these questions showing your work plz

Mason and christian go to the movie theater and purchase refreshments for their friends. mason spends a total of $45.75 on 3 bags of popcorn and 6 drinks. christian spends a total of $71.50 on 6 bags of popcorn and 4 drinks. write a system of equations that can be used to find the price of one bag of popcorn and the price of one drink. using these equations, determine and state the price of a drink, to the nearest cent.

The amount cami raised during last year’s charity walk, $45.50, is 7/10 of the amount she raised this year. which equation represents n, the number of dollars she raised this year?