\(a,x+y=\sqrt{5^2+7^2}=\sqrt{74}\left(pytago\right)\)
Áp dụng HTL:
\(\left\{{}\begin{matrix}5^2=x\sqrt{74}\\7^2=y\sqrt{74}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{25\sqrt{74}}{74}\\y=\dfrac{49\sqrt{74}}{74}\end{matrix}\right.\)
\(b,\) Áp dụng HTL:
\(14^2=16y\Leftrightarrow y=\dfrac{196}{16}=12,25\\ \Leftrightarrow x=16-12,25=3,75\)