-12*3i7/15+3i1/2:5= 3i3/4:3/10-(-1i1/6):7/5= 2i3/4:(3/4-2i1/6)-1/2=

-12 * 3i7/15 + 3i1/2 : 5 = = -12 * 52/15 + 7/2 * 1/5 =  = -208/5 + 7/10 =  = -416/10 + 7/10 =  = -409/10 =  = 40 i 9/10 3 i 3/4 : 3/10 - (-1 i 1/6) : 7/5 = = 15/4 * 10/3 + 7/6 * 5/7 =  = 25/2 + 5/6 =  = 75/6 + 5/6 =  = 80/6 =  = 13 i 2/6 =  = 13 i 1/3 2 i 3/4 : (3/4 - 2 i 1/6) - 1/2 = = 11/4 : (3/4 - 13/6) - 1/2 = = 11/4 : ( 9/12 - 26/12) - 1/2 =  = 11/4 : (- 17/12) - 1/2 =  = 11/4 * (-12/17) - 1/2 =  = 33/17 - 1/2 =  = 66/34 - 17/34 =  = 49/34 =  = 1 i 15/34

odp. w zalaczniku