Упростите выражение.

Решите задачу:

$\frac{{a}^{2}}{(a-b)(a-c)}+\frac{{b}^{2}}{(b-c)(-(a-b))}+\frac{{c}^{2}}{-(a-c)(-(b-c))} \\ \\ \frac{{a}^{2}(b-c)-{b}^{2}(a-c)+{c}^{2}(a-b)}{(a-b)(a-c)(b-c)}$

$\frac{{a}^{2}b-{a}^{2}c-{ab}^{2}+{b}^{2}c+{ac}^{2}-{bc}^{2}}{({a}^{2}-ac-ab+bc)(b-c)} \\ \\ \frac{{a}^{2}b-{a}^{2}c+{ac}^{2}-{ab}^{2}+{b}^{2}c-{bc}^{2}}{{a}^{2}b-{a}^{2}c-abc+{ac}^{2}-{ab}^{2}+abc+{b}^{2}c-{bc}^{2}} \\ \\ \frac{{a}^{2}b-{a}^{2}c+{ac}^{2}-{ab}^{2}+{b}^{2}c-{bc}^{2}}{{a}^{2}b-{a}^{2}c+{ac}^{2}-{ab}^{2}+{b}^{2}c-{bc}^{2}}=1$