Respuesta :

37
3(2*4+5)+2(3-4)
3(8+5)+2(-1)
3(13)+2(-1)
39+2(-1)
39+-2
39-2
37
If a=4, then the new equation would be 3(8+5) + 2(3-4)

3(13) + 2(-1)
39 + (-2)
37

Hope I could help :D