knowing the answer is between 3 & 4 plug those as x and see what you get for answers than adjust the number accordingly
3^3+2(3) = 33 so its higher than 3
4^3 + 2(4) = 72 so it is lower than 4
try the middle so try 3.5
3.5^3 + 2(3.5) = 49.875
question states use 1 decimal place so now try 3.6
3.6^3+2(3.6) = 53.856
3.5 is closest
