Answer:
+
=
![6.373 * 10^(13)](https://img.qammunity.org/2019/formulas/chemistry/college/8hz3233b9qo6fh7jgxgqnmlnjbmevux59l.png)
Step-by-step explanation:
Given
![6.28 * 10^(13)](https://img.qammunity.org/2019/formulas/chemistry/college/55mo8itxs4somftiz1um8kol6ly6wd2pnt.png)
![9.30 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/51gxjonf82fonlogrgl3iwn9gh6vv1fq6b.png)
Required
Add
The are quite a number of ways to solve this question.
I'll solve it using two methods
Method 1
+
![9.30 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/51gxjonf82fonlogrgl3iwn9gh6vv1fq6b.png)
Expand Both indices
![(6.28 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10) + (9.30 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10)](https://img.qammunity.org/2019/formulas/chemistry/college/xc3kr0muvejkpjtvz7qz60wn3ys7cnwkx8.png)
Perform multiplication
=
![62800000000000 + 930000000000](https://img.qammunity.org/2019/formulas/chemistry/college/23lkrqzjw8x4d9zy5i51vwjioxrwk963dp.png)
Add
![= 63730000000000](https://img.qammunity.org/2019/formulas/chemistry/college/7gitvmuun2ju0u3vknx8dtpyn6mjq7nccs.png)
Convert to index form
![= 6.373 * 10^(13)](https://img.qammunity.org/2019/formulas/chemistry/college/u2johy57r2px7ovaxm3dpck53nrvuund1z.png)
Method 2
+
![9.30 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/51gxjonf82fonlogrgl3iwn9gh6vv1fq6b.png)
Expand
--- According to law of indices
+
![9.30 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/51gxjonf82fonlogrgl3iwn9gh6vv1fq6b.png)
Re-order
+
![9.30 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/51gxjonf82fonlogrgl3iwn9gh6vv1fq6b.png)
Factorize
![(10^(11)-is-a-common-factor)](https://img.qammunity.org/2019/formulas/chemistry/college/5wlxt7l2n6hv7n3i7bun6q9jd1rx4dod2i.png)
![10^(11) (6.28 * 10^(2) + 9.30)](https://img.qammunity.org/2019/formulas/chemistry/college/ob38fwzb19xuwu9foo0pq4pmrnnxn0w89o.png)
Expand
![6.28 * 10^(2) -to-6.28 * 100-to-628](https://img.qammunity.org/2019/formulas/chemistry/college/kwmwjvrp1prj0ai0dajjqe335lxu4pfv1a.png)
![10^(11) (628 + 9.30)](https://img.qammunity.org/2019/formulas/chemistry/college/odc8xgrknf29iabi3mk4q6te556izawud1.png)
Add 628 and 9.3
![10^(11) (637.3)](https://img.qammunity.org/2019/formulas/chemistry/college/7vustpa7cbg0ssyg3lryacnxrr5znhptgo.png)
Reorder
![637.3 * 10^(11)](https://img.qammunity.org/2019/formulas/chemistry/college/s10d0d8dj9e24gn58mlenzndlijmz47m3j.png)
Represent in scientific notation
![6.373 * 10^(11) * 10^(2)](https://img.qammunity.org/2019/formulas/chemistry/college/jptcouisnnocex6b5g3suwn2r2riyvzvjv.png)
![6.373 * 10^(13)](https://img.qammunity.org/2019/formulas/chemistry/college/8hz3233b9qo6fh7jgxgqnmlnjbmevux59l.png)