I have a bunch of questions here. Some I am unsure about the answer, some I just can't do.

1.Simplify(2a^{7}x 50a^{3})^{-1/2}

For this one I would assume you do inside the brackets first, and then do the power of negative 1/2, so: (100a^{10})^{-1/2}... THIS is the answer I get: 0.1a^{-5}

Is that right?

2.Writelog 8 + log 16in terms of log 2.

I ended up going: log 2^{3}+ log 2^{4}, and then 3 log 2 + 4 log 2, and then 7 log 2, and then log 2^{7}. I'm not sure if I should go back a step and the answer is 7 log 2

3.Simplify(x^{2}+ 3x - 10)(x + 5)^{-1}this one I can't do because I don't know whether to expand the brackets first, or what to do with the -1 power!!!

Please help.