Add or subtract as indicated:

a. 5.80×10^9s + 3.20×10^8s
b. 4.87×10^-6m - 1.93×10^-6m
c. 3.14×10^-5kg + 9.36×10^-5kg
d. 8.12×10^7g - 6.20×10^6g

how do i solve these?

Gabby calls her cousin who lives in a different state and tells her to turn her radio to channel 98.7 so they can listen to their favorite song that is playing. her cousin turns her radio to 98.7, but does not hear the same song gabby hears. which most likely explains why?