To solve the equation \( 6^{x+1} + 35 \cdot 6^{x-1} = 71 \), we can start by rewriting the terms for easier manipulation.
First, we can express \( 6^{x+1} \) as \( 6^x \cdot 6 \) and \( 35 \cdot 6^{x-1} \) as \( 35 \cdot \frac{6^x}{6} \):
\[ 6 \cdot 6^x + 35 \cdot \frac{6^x}{6} = 71 \]
Simplifying \( 35 \cdot \frac{6^x}{6} \) gives us:
\[ 6 \cdot 6^x + \frac{35}{6} \cdot 6^x = 71 \]
Now, combine the terms on the left side:
\[ \left(6 + \frac{35}{6}\right) 6^x = 71 \]
To combine \( 6 + \frac{35}{6} \), we first find a common denominator (which is 6):
\[ 6 = \frac{36}{6} \quad \text{so} \quad 6 + \frac{35}{6} = \frac{36 + 35}{6} = \frac{71}{6} \]
Now, substituting this back into the equation, we have:
\[ \frac{71}{6} 6^x = 71 \]
To eliminate 71 from both sides, we can divide by 71:
\[ \frac{6^x}{6} = 1 \]
Multiplying both sides by 6 gives us:
\[ 6^x = 6 \]
This means:
\[ x = 1 \]
Thus, the solution to the equation \( 6^{x+1} + 35 \cdot 6^{x-1} = 71 \) is:
\[ \boxed{1} \]
