For what value of a does the equation ax^2-3cx-5=0 have 1 as one of its root? PLZ HELP. Will give brainliest

Ican interpret and represent the remainder in division calculations sensibly for the context (eg 27.4 in calculating average height in cm: $27.44 if it represents an amount of money) solve the following problems. 15) the wildlife park charges $25.50 dollars per person to enter their park if the park made $15096 dollars today, how many people entered the park? 16) ms adams plus 2,230 other keen runners ran a marathon: between them they ran 94817.5km. how many km did each competitor run?