On the first question 67.6 it has no x

You are correct to point out the notation. In the expression $67 \cdot 6^x$, the dot ($\cdot$) represents multiplication, not a decimal point. So, it means $67 \times 6^x$.

The original equation was:

$$8 \cdot 7^x = 67 \cdot 6^x$$

This means:

$$8 \times 7^x = 67 \times 6^x$$

My solution correctly interpreted this as $67 \times 6^x$. If it were $67.6^x$, the problem would be written as $(67.6)^x$.