Let \( x \) be the number of pages Susan read yesterday. According to the problem, we have the following equation:
\[ 17 = \frac{4}{3}x - 8 \]
To solve for \( x \), we first add 8 to both sides:
\[ 17 + 8 = \frac{4}{3}x \]
This simplifies to:
\[ 25 = \frac{4}{3}x \]
Next, we multiply both sides by \( \frac{3}{4} \) to isolate \( x \):
\[ x = 25 \times \frac{3}{4} \]
Calculating that gives:
\[ x = \frac{75}{4} = 18.75 \]
Since the number of pages read must be a whole number, let's recheck the calculations:
We go back to:
\[ \frac{4}{3}x - 8 = 17 \]
Rearranging gives:
\[ \frac{4}{3}x = 25 \]
Now, multiply by \( \frac{3}{4} \):
\[ x = 25 \cdot \frac{3}{4} = 18.75 \]
To clarify, if we want it in whole pages, typically we round down or consider an adjacent approximate that's whole, given the context.
However, if the context allows or the problem is strict, we can round:
So, rounding \( 18.75 \) down, we can conclude:
Ultimately, since Susan cannot read a fraction of a page and the context suggests integer pages, we can reaffirm:
When adjustments made, she could have read 19 pages yesterday or, if exact, retained as \( 18 \).
Thus, summarized: Yesterday, Susan read either 19 pages or 18 if strict integers were needed in scenarios.