a) \sqrt{28}= \sqrt{2*2*7}=\sqrt{4*7}=2\sqrt7
b) \sqrt{32}=\sqrt{2*2*2*2*2}=\sqrt{2^2*2^2*2}=4\sqrt2
c) \sqrt{500}=\sqrt{2*2*5*5*5}=\sqrt{2^2*5^2*5}=10\sqrt5
d) \sqrt{810}=\sqrt{2*3*3*3*3*5}=\sqrt{81*10}=\sqrt{3^2*3^2*10}=9\sqrt{10}
e) \sqrt{99}=\sqrt{3*3*11}=\sqrt{9}*\sqrt{11}=3\sqrt{11}
f) \sqrt{80}=\sqrt{2*2*2*2*5}=\sqrt{2^2}*\sqrt{2^2}*\sqrt5=2*2*\sqrt5=4\sqrt5
g) \sqrt{176}=\sqrt{2*2*2*2*11}=\sqrt{2^2}*\sqrt{2^2}*\sqrt{11}=4\sqrt{11}
h) \sqrt{12500}=\sqrt{2*2*5*5*5*5*5}=\sqrt{2^2*5^2*5^2*5}=2*5*5\sqrt5=50\sqrt{5}