Solve for x
3-x=5
the solution is x =?

How to do this , and can some one explain

Abarbecue sold 26 hamburgers and hot dogs. hamburgers sell for $3.50 each and hot dogs sell for $2.00 each. if the barbecue made $70 in sales, determine and state the number of hot dogs sold.

Do,h = (7, 9) (14, 18) the scale factor is