I need help with this problem. I know the answer is (2.1630342940) but I have no idea how to get there. I know i need to sum the forces for each.

Block m1( 6 kg ), lies on an incline plane with a coefficient of kinetic friction of 0.15. m1 is connected to mass m2 by a massless rope passing over a pulley. As m2 moves down, determine the acceleration of m1 up the incline, given θ = 250 and m1 = m2.

net force=total mass*acceleration

force pulling: m2*g
force retarding: fricion + gravity on m1 down the plane.
force retarding: -m1*g*sinTheta-mu*m1*g*cosTheta

so net force= (m1+m2) a
m2*g -m1*g*sinTheta-mu*m1*g*cosTheta=(m1+m2) a