a)x+2x++++150x-11324x<52-3x16
150x151:2=11325x
11325x-11324x=x
x<52-48
x<3
x∈1,2,3
b)x+2x+++200x=60300
200x201:2=20100x
x=60300:20100
x=3
c)2x+4x+++200x-324<x+3x+++199x+176
100x201:2-324<100x200+176
10050x-324<10000+176
50x-324<176
50x<176+324
50x<500
x<500:50
x<10
x∈1,2,3,4,5,6,7,8,9