Answer
$pH=6$
Work Step by Step
We are given the function:
$$f(x)=\dfrac{6.5x^2-20.4x+234}{x^2+36}.\tag1$$
Graph the function $f$ and the line $x=42$.
The intersection point between the functions's graph and the line $x=42$ is $(42,6.024)$. So the pH level $42$ minutes after a person eats food containing sugar is about $6$.
