Solve for k
k=4
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3k-5-7k=-21
Subtract 7k from both sides.
-4k-5=-21
Combine 3k and -7k to get -4k.
-4k=-21+5
Add 5 to both sides.
-4k=-16
Add -21 and 5 to get -16.
k=\frac{-16}{-4}
Divide both sides by -4.
k=4
Divide -16 by -4 to get 4.
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