Question

An object of mass 3.8 kg is pushed directly from rest along a horizontal surface, a distance of 1.2, and reaches a speed of 2.6 m/s by the end of the push. The frictional force acting is 6.7 N. Determine the acceleration of the object while being pushed.

Answer 1

As far as I can tell you have a lot of extraneous data.
Here's how I would solve it:

d=1.2 (assuming these are meters)
Vi=0 m/s
Vf=2.6 m/s
a=? m/s^2

Use \[Vf^{2}=Vi ^{2}+2ad\]
\[(2.60^{2}=(0^2)+2(a)1.2)\]