ok , lots of questions=lower standard of explanation
just answers
5. 8.5 times 10^12
6. 0.001260-7,003,000
7.3.843 times 10^4
9. x=1
10. 7^(x+5)=49^(x+3)
11. 1.03
12. 25,700(0.85)^x
13. 10a√a
14. [tex]2 x^{2} y^{4} \sqrt[3]{5x^{2}} [/tex]
15.6√3
16. [tex] \frac{2 \sqrt{3x} }{3x} [/tex]
17. [tex] 4 \sqrt[3]{x^{2}} [/tex]
18.[tex]64 x^{ \frac{10}{3} } y^{ \frac{5}{2} } [/tex]
19.√109
20. (8,(3/2))
21. 5 units