Given:
Simplified value is 3a-2.
To find:
The expression which has a simplified value of 3a - 2.
Solution:
In option A,
[tex]-8+3a+10-a=(-8+10)+(3a-a)[/tex]
[tex]-8+3a+10-a=2+2a\neq 3a-2[/tex]
In option B,
[tex]-10-5a+12+8a=(-10+12)+(-5a+8a)[/tex]
[tex]-10-5a+12+8a=2+3a\neq 3a-2[/tex]
In option C,
[tex]-a+4+5a-a-6=(-a+5a-a)+(4-6)[/tex]
[tex]-a+4+5a-a-6=3a-2[/tex]
In option D,
[tex]-6a+9a+4-2=3a+2\neq 3a-2[/tex]
Therefore, the correct option is C.
