PLEASE HELP I NEED THE ANSWER IN 5 MINS GIVING BRANLY OUT (ANSWER ALL OF THEM FOR BRANLYEST)

Hiroaki wants to find 3 3/4 - 7/8 explain why he must rename 3 3/4 to do the subtraction.

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.

The square root of 9x plus 7 plus the square rot of 2x equall to 7