-1/8d - 4 = -3/8
move -4 to the other side
sign changes from -4 to +4
-1/8d-4+4=-3/8+4
-1/8d=-3/8+4
pretend that 4 has a denominator which is 1
-1/8d=-3/8+4/1
find the common denominator for 4/1 which is 8
multiply by 8 for 4/1
4(8)/1(8)=32/8
-1/8d=-3/8+32/8
-1/8d=29/8
multiply both sides by -8/1 to get +d
-1/8d*-8/1=29/8(-8/1)
Cross out 8 and -8, divide by 8 and then becomes 29*1*-1=-29
Cross out -1/8 and -8/1, divide by 8 and 1. Then becomes 1*1*d=d
Answer:
d=-29