Question 13: Performing the calculation \(\left(x-\frac{1}{2}\right)^{2}+4-y \) we get
\(\left(x-\frac{1}{2}\right)^{2}+4-y =x^{2}-2 \cdot x \cdot \frac{1}{2}+\left (\frac{1}{2}\right)^{2}+4-y=x^{2}-x+\frac{1}{4}+4-y=x^{2}-x-y+ \frac{17}{4} \)
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