Answer
4.3
Work Step by Step
In order to follow order of operations, we first multiply and then we add and subtract:
$7(0.6)+0.9-3(0.4)+0.4$
=$(7\times0.6)+0.9-(3\times0.4)+0.4$
=$(4.2)+0.9-(1.2)+0.4$
=$(4.2+0.9)-1.2+0.4$
=$(5.1)-1.2+0.4$
=$(5.1-1.2)+0.4$
=$(3.9)+0.4$
=$4.3$