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I really need help with algebraic proofs someone please help!!!

statement 4(5n+7)-3n=3(4n-9)
prove n=-11
and the reason​

User Teilmann
by
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1 Answer

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15 votes

Answer/Step-by-step explanation:

4(5n + 7) - 3n = 3(4n - 9)

20n + 28 - 3n = 12n - 27

17n + 28 = 12n - 27

-12n -12n

-----------------------------

5n + 28 = -27

-28 -28

-----------------------

5n = -55

÷5 ÷5

----------------

n = -11

The reason why n = -11 is the answer is that when plugged back into the equation, the equation will equal.

4(5n + 7) - 3n = 3(4n - 9)

4(5(-11) + 7) - 3(-11) = 3(4(-11) - 9)

4(-55 + 7) + 33 = 3(-44 - 9)

4(-48) + 33 = 3(-53)

-192 + 33 = -159

-159 = -159

I hope this helps!

User Guillaume Georges
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