find the value ............

Step-by-step explanation:
[tex]\tt{2-3a+7 =8a+3-a }[/tex] ⠀
[tex]\tt{8a-a+3a=2+7-3 }[/tex] ⠀
[tex]\tt{11a-a=9-3 }[/tex] ⠀
[tex]\tt{10a=6 }[/tex] ⠀
[tex]\tt{ a=\dfrac{6}{10} }[/tex] ⠀
[tex]\tt{a=\dfrac{3}{5} }[/tex] ⠀
[tex]\boxed{\large{\bold{\blue{ANSWER~:) }}}}[/tex]