Use the difference of squares identity to write this polynomial expression in factored form: 9x2 − 49.

Use the elimination method to solve the system of equations -x+5y=-4 and 4x+3y=16

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

Anyone know? is appreciated! will mark brainliest if correct!