13a.) If you're dividing and the base (in this case the base is 10) is the same, subtract the exponents.
[tex] {10}^{7} \div {10}^{5} = {10}^{7 - 5} = {10}^{2} [/tex]
13b.) If you're multiplying and the base is the same, then you add the exponents:
[tex] {s}^{2} \times {s}^{3} \times s = {s}^{2 + 3 + 1} = {s}^{6} [/tex]
13c.) This is similar to 13b:
[tex] {6}^{4} \times {6}^{3} \times 6 = {6}^{4 + 3 + 1} = {6}^{8} [/tex]
