Explanation:
Okay so remember the BODMAS rule where u start with brackets right; Since we're proving that RHS =LHS ,we look at the side which is more complicated and solve it first.
RHS: -4a-(8a+1) =-169
-4a-8a-1=-169
-4a-8a= -169+1 ( N:B like terms)
-12a= -168
-12a/-12= -168/-12
a= 14
Then go back to the original equation and subtitute .
where u see a u put the value u calculated.
-4a-(8a+1)=-169
-4(14)-(8(14)+1)= -169
-169= -169 and u DONE!!