these are scientific notations
first:
[tex] \\ 3.6 \times {10}^{3} = 3600 \\ \\ 6.1 \times {10}^{3} = 6100[/tex]
so :
[tex]6100 + 3600 = 9700[/tex]
now you can change it back to scientific notations
[tex]9700 = 9.7 \times {10}^{3} [/tex]
or you can do that in an easier way: (this situation goes only if the powers of 10s are equal)
[tex]3.6 \times {10}^{3} + 6.1 \times {10}^{3} = 9.7 \times {10}^{3} [/tex]
good luck
