giúp e với ạ. Đang cần gấp ajaaa!!

$\begin{array}{l}
{a^2} + 2025 = {a^2} + ab + bc + ca = \left( {a + b} \right)\left( {a + c} \right)\\
tt:{b^2} + 2025 = \left( {b + c} \right)\left( {b + a} \right),{c^2} + 2025 = \left( {c + a} \right)\left( {c + b} \right)\\
\dfrac{{{a^2} - bc}}{{{a^2} + 2025}} + \dfrac{{{b^2} - ca}}{{{b^2} + 2025}} + \dfrac{{{c^2} - ab}}{{{c^2} + 2025}}\\
 = \dfrac{{{a^2} - bc}}{{\left( {a + b} \right)\left( {a + c} \right)}} + \dfrac{{{b^2} - ca}}{{\left( {b + c} \right)\left( {b + a} \right)}} + \dfrac{{{c^2} - ab}}{{\left( {c + a} \right)\left( {c + b} \right)}}\\
 = \dfrac{{\left( {{a^2} - bc} \right)\left( {b + c} \right) + \left( {{b^2} - ca} \right)\left( {c + a} \right) + \left( {{c^2} - ab} \right)\left( {a + b} \right)}}{{\left( {a + b} \right)\left( {a + c} \right)\left( {b + c} \right)}}\\
 = \dfrac{{{a^2}b + {a^2}c - {b^2}c + b{c^2} + {b^2}{c^2} + {b^2}a - {c^2}a - {a^2}c + {c^2}a + {c^2}b - {a^2}b - a{b^2}}}{{\left( {a + b} \right)\left( {a + c} \right)\left( {b + c} \right)}}\\
 = 0
\end{array}$