Question 15Fill suitable signs (+ or -) into the blanks to get a correct equation: 15 __ 8 __ 4 __ 5 = 1615 + 8 - 4 - 5 = 1615 + 8 + 4 - 5 = 1615 - 8 - 4 + 5 = 1615 - 8 + 4 + 5 = 16