Answer:
2.79 * 10^4
Step-by-step explanation:
6.4 x 10^3+ 1.4 x 10^4+ 7.5 x 10^3
The exponents need to be the same
6.4 x 10^3+ 14 x 10^3+ 7.5 x 10^3
Add the numbers
6.4 + 14+ 7.5 =27.9
Multiply by the exponent
27.9 * 10 ^3
But this is not in scientific notation
Move the decimal one place to the left and add one to the exponent
2.79 * 10^4
