Question

a3+a2-21a-45=0

Answer 1

a3 + a2 - 21a - 45 = 0

➖ 3a + 2a - 21a - 45 = 0
➖ -16a - 45 = 0
➖ -16a = 45
➖ a = 45 / (-16)
➖ a = ( -45)/16

If represented in the decimal form; a = 2.8125

Hope I could help