I really need help on geometry

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Kathleen's gross annual salary is $56,820. what is the maximum amount of rent she can afford to pay? round your answer to the nearest dollar. question 1 options: $1146 $1326 $1656 $2368

Joseph haydn pet store offers wide variety of leashes for dogs. the store purchases one popular type of leash from its manufacturer for $4.38 each. joseph haydn pets marks up leashes at a rate of 238% of cost. what is the retail price of the popular leash?