Explain how to check the quotation from a division problem

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Find the area of the unshaded square

Can you me find the missing length. i attached an image.