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?

i believe the answer would be:

d. violin, clarinet, french horn, and tuba

i would like to make dinner for my mom, dad, and sister

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.