The equation is not setup properly, possibly it is your teacher's fault.
From external research, I would say the answer is x = -12.
<h3>
Answer is 5(6a+7)</h3>
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The GCF is 5, which can be factored out of the expression
Note how
30a = 5*6a
35 = 5*7
So we see the common factor between the two terms. You use the distribution property to pull out that 5. If you were do distribute the 5 back in, you'd get
5(6a+7) = 5*6a+5*7 = 30a+35
