Answer:
a. 3(x-7)+2=2x-1
3x-21+2=2x-1
3x-19=2x-1
+19 +19
3x=2x+18
-2x -2x
x=18
b. 2x-(5-x)=3x+2(x-7)
2x-5+x=3x+2x-14
3x-5=5x-14
-14 -14
3x+9=5x
-3x -3x
9/2=2x/2
x=9/2