Answer: 27.987
Explanation: if x is 10.9 then you start with 0.207+2.1^3(10.9-7.9). You start with (10.9-7.9) because it’s in parentheses (PEMDAS) so 10.9-7.9=3 then you do 2.1^3= 9.26 now you have 0.207+9.26*3 so you multiply 9.26*3=27.78 finally you have 0.207+27.78= 27.987