(×+340)-152=214

×+340=214+152

×+340=366

×=366-340

×=26

500+(×+140)=2056

×+140=2056-500

×+140=1556

×=1556-140

×=1416

800:y-300=500

800:y=500+300

800:y=800

y=800:800

y=1

(a+200):400=2

a+200=400×2

a+200=800

a=800-200

a=600