Answer:
3.56*10^13
Step-by-step explanation:
8.9* 10^4 * 4*10^8
Multiply the number out front and then the exponents
8.9 * 4 * 10^4 * 10^8
When we multiply powers when the bases are the same, we add the exponents
35.6 * 10^(4+8)
35.6 *10^12
But this is not in proper scientific notation. Only one digit before the decimal
Move the decimal one place to the left, that means we need to add 1 to the exponent
3.56 *10^(12+1)
3.56 * 10^13
