What is the acceleration of the block?

Question

A 9 kg block experiences two external forces acting on it simultaneously. Force A has a magnitude of 20 N and points in the positive direction. Force B has a magnitude of 4 N and points in the negative direction. What is the acceleration of the block? Report your answer to 1 decimal place. 

Answer 1

a = F_net / m

F_net = (20 - 4)N in the positive direction

m = 9 kg

Plug the numbers into the equation for a and get a in units of m/s².