Plz help :( I don’t understand

PLEASE MARK AS BRAINLIST
Answer:
1. 2x-20+2x-15=13
4x-35=13
4x=13+35
4x=48
x=12
2. x-4+9=2x-4
2x-x= -4+9+4
x=9
3. IJK=41+130=171
4. KJD=88-50=38