Answer:
7 * 10^7
Explanation:
The decimal point of the the original number is after the last zero:
70000000.
For scientific notation, you need a number from 1 to under 10. You will have 7. You must put a decimal point just to the right of the 7, like this:
7.0000000
The number of decimal places the decimal point moved is 7, so the exponent of the 10 is 7.
70000000 = 7 * 10^7