How to get the answer for 2 3/4 gallons and 5/8 to equal 1 23/32

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

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made. determine an equation to model his situation?