Can someone help me with calulating gravitational force?

Question

I have an assignment due in a couple of hours for astronomy. I've been working on this for a few hours now, but I'm not really familiar with algebra. Any help would be greatly appreciated! The question is as follows:

 

The gravitational force between two objects follows Newton's gravitational law F=G\frac{m_1m_2}{r^2}F=Gm1m2r2, where G=6.67\times10^{-11}\frac{N\:m^2}{kg^2}G=6.67×10−11Nm2kg2. Using the distance between the earth and Moon as R_{Earth-Moon}=3.844\times10^8REarth−Moon=3.844×108m and the mass of the Moon as m_{Moon}=7.35\times10^{22}kgmMoon=7.35×1022kg. What would the force of gravity be on a person 90 kg on Earth due to the Moon (in Newtons) be?

Answer 1

F= ma = Gm1m2/r^2

 

In the question, you are given: G, the mass of the person (m1), the mass of the moon (m2), and the radius (r) 

 

Plug in and solve