Hey there!
So, first we would do a first part if this problem.
[tex]4.2*105[/tex]
This would equal . . . .
[tex]\boxed{\boxed{441}}[/tex]
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Then we would do the second part of the problem.
[tex]5.3*105[/tex]
This would equal . . . .
[tex]\boxed{\boxed{556.5}}[/tex]
(By adding both (441) and also (556.5)
This would equal . . .
[tex]\boxed{\boxed{\boxed{997.5}}}[/tex]
Hope this helps.
~Jurgen
