(also made another mistake, used 1.67 M/S^2 not 1.17)

sum of all x = 3.50N +(-1.20N)+ F3x = 1.17m/s^2

sum of all y = 0+ 1.78N + F3y = -0.677m/s^2

object has mass 6.17 kg (I think this might need to be used since the sum of both values is in Newtons and I guess everything has to be the same unit to be able to work with them?)

and I got it

answer is 4.92N ,-5.96 N

I had to get the sum of all forces for each by multiplying 6.17KG by the a for x and the same for y.. then the rest was elementary mathematics.