Let's solve the next equation:
[tex]6+(c+8)=13[/tex]We need to find the value for c, this value is correct when we replaced it with a number and the equality equation becomes true.
First, subtract both sides by 6
[tex]6-6+(c+8)=13-6[/tex][tex]c+8=7[/tex]Now, subtract both sides by 8
[tex]c+8-8=7-8[/tex][tex]c=-1[/tex]Replacing the c value to verify:
[tex]6+(-1+8)=13[/tex][tex]6+7=13[/tex]The c value is correct.