Yes, 4/8 and 1/2 are equivalent, because 4/8 reduced to simplest form is 1/2.
For the first one, you did good. I will just suggest a couple things.
Statement Reason
JK ≅ LM Given
<JKM ≅ < LMK Given (You did both of these steps so well done.)
MK ≅ MK Reflexive Property (Your angle pair is congruent but isn't one of the interior angle of the triangles you are trying to prove.)
ΔJMK ≅ ΔLKM SAS
Problem 2: (You also have a lot of great stuff here.)
Statement Reason
DE ║ FG Given
DE ≅ FG Given
<DEF≅<FGH Given
<EDF≅<GFH Corresponding Angles (You don't need to know that F is the midpoint but you got corresponding angle pair which is correct.)
ΔEDF≅ΔGFH ASA
<DFE≅<FHG CPCTC
Correct the answer is -55
Let change 7/8 and 1/5 into decimal point so 0.88 and 0.2
0.88-0.2 =0.68
then we want 5 equal length so we divided
0.68 / 5 =0.14
