7.003 x 10 to the power of 4

In scientific notation, just move the decimal point over however many numbers are in the power. 

In 7.003 • 10^4, move the decimal point over 4 places to the right, (or left if it's negative) making it 70,030

Here you need to follow the order of operations.
Parenthesis
Exponents
Multiply
Divide
Add
Subtract
So, following these steps the first thing you would do is multiply 10 to the power of 4 (10^4).
10^4 = 10,000
Next, you would just multiply 7.003 * 10,000 
7.003 * 10,000 = 70,030
Hope this helps!

The correct answer would be the fourth choice

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable