ATENGINA69IN ATENGINA69IN Math Answered determine a number that must be added to make each of the ff. a perfect square trinomial. 1. x2 + 2x + __ 2. x2 -8x + __ 3. r2 - 16r + __ 4. t2 + 20t + __ 5. s2 - 2/3s + __