Block diagrams can be different and still works for the same system?
Your answer is incorrect in the sense that you produce an error signal from signals that have different physical dimensions. In your system, you subtract temperature units from volts, which is not a valid operation ("you can only subtract apples from apples"). The unit conversion in the feedback loop is missing.

The answer in the book is actually pretty close to what you intended, but it assumes you understand the following equivalence. These two closed-loop systems have the same reference to measured output transfer function:



Proof: name the following


Unit Conversion := \$F(s)\$
Controller := \$C(s)\$
Plant := \$G(s)\$


For the first system:

$$\begin{cases}
y(s) = C(s)G(s)e(s)\\
e(s) = F(s)r(s)-F(s)y(s)
\end{cases}$$

$$y(s) = C(s)G(s)[F(s)r(s)-F(s)y(s)]$$
$$y(s) = \frac{C(s)G(s)F(s)}{C(s)G(s)F(s)+1}r(s)$$

For the second system:

$$\begin{cases}
y(s) = C(s)G(s)F(s)e(s)\\
e(s) = r(s)-y(s)
\end{cases}$$

$$y(s) = C(s)G(s)F(s)[r(s)-y(s)]\\$$
$$y(s) = \frac{C(s)G(s)F(s)}{C(s)G(s)F(s)+1}r(s)\\$$

End of proof: both systems have the same \$r(s)\$ to \$y(s)\$ transfer function.