Answer:
2.389 x 10^5
Explanation:
First, write both numbers out. Move the decimal point right however many times the exponent says. For 8.9, we move the decimal right 3 times, and we would move it right 5 times for 2.3.
230000
+ 8900
238900
Now let's convert this to scientific form. The beginning number in scientific form has to be between 1 and 10, so move the decimal point left until you get a number that fits. Here, we will move it 5 times.
2.38900
Because we've moved it left 5 times, we make the exponent 5.