How to find acceleration from given 2 masses and acceleration?

[Sneakatone]

an astronaut (with a spacesuit) of mass 90 kg is tethered to a 750 kg satellite. By pulling on the tether, she accelerates toward the satellite at 0.55 m/s^2. What is the acceleration of the satellite toward the astronaut?

I do not know how to start since I am guessing gravity doesn't apply

 

[SteamKing]

Why is the astronaut accelerating toward the spacecraft after pulling on the tether?
Haven't you learned about forces and accelerations? Newton? Bueller?

 

[Sneakatone]

ok I got I now.
I did ma=ma to find the missing acceleration.
thanks!