I mean it’s pretty simple really! Just plug in 0.5 for all the a’s in the equation so you equation will look like this
0.5^2+ 0.4(0.5) and now that you have your equation solve it normally! Remember to use PEMDAS
So....
0.5^2= 0.25 first we do the exponent
.25+0.4(0.5) here’s what we have now
0.4(0.5) = 0.2 now we do multiplication
.25+0.2= .45 finally we do addition and
it will give us a result of .45 so your answers is B