Hi there! Hopefully this helps!
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[tex]-30=5k+5[/tex]
Swap sides so that all variable terms are on the left hand side.
[tex]5k+5=-30[/tex]
Subtract 5 from both sides.
[tex]5k=-30-5[/tex]
Subtract 5 from −30 to get −35.
[tex]5k=-35[/tex]
Divide both sides by 5.
[tex]k=\frac{-35}{5}[/tex]
You can also do "5(-7) + 5 = ??" For proof.