if you know the definition of expand (to increase or make bigger)
then this will be easy.
when ever it asks for expanded for that means your answer has to be bigger than the number your given.
for your question:
you have 7,080,267
so u first do the biggest value which is the first 7 on the left.
and then work your way down to the smallest which would be 7 on the right.
7000000
000000
80000
0000
200
60
7
that is the numbers expanded
but now u have to write it in the fom so you just add a + after each number
7000000+000000+80000+0000+200+60+7
you can shorten it by removing the numbers with no value:
7000000+80000+200+60+7