4c+5
hope that helps you out
The sum (c−4)+(3c+9) is 4C+5
(c−4)+(3c+9)
⇒C-4+3C+9
⇒(C+3C)+(-4+9)
⇒4C+5
Learn more about addition here: https://brainly.com/question/4721701
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