Ребят,очень срочно)))

[latex] \frac{14cos50^\circ \cdot sin130^\circ }{cos10^\circ } = \frac{14cos50^\circ \cdot sin(180^\circ -50^\circ )}{cos10^\circ } = \frac{7\cdot 2cos50^\circ \cdot sin50^\circ }{cos10^\circ } =\\\\= \frac{7\cdot sin100^\circ }{cos10^\circ } = \frac{7sin(90^\circ +10^\circ )}{cos10^\circ } = \frac{7cos10^\circ }{cos10^\circ } =7[/latex]