4. Resolva as operações: a)

4. Resolva as operações: a) $3.10^{2}+4.10^{2}$ b) $3.10^{2} \times 2.10^{3}$ c) $5.10^{4} \times 8.10^{3}$ d) $8.10^{6}+4.10^{3}$ e) $4.10^{3}+5.10^{3}$ f) $2.10^{4} \times 2.10^{3}$ g) $9.10^{3}+3.10^{6}$ h) $15.10^{8}+3.10^{4}$ i) $24.10^{18}+6.10^{9}$