We want to add two numbers that are written in scientific notation.
(7.8* 10^7)+(9.9* 10^7)Notice that the exponent of 10 is the same for both numbers. To add the expressions, we can factor out 10^7.
Recall that the first factor of a number written in scientific notation must be greater than or equal to 1 and less than 10. Therefore, we need to rewrite 17.7 as the product of 1.77 and 10. Then, we can simplify.
