(3а-4)-4
how do you simplify?

If 1 is divided by the sum of y& 4.the result is equal to 3 divided by 4, find the value of m

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?

Need this asap if anyone can i would be very grateful. if you could show workings that would really