[tex]( \sqrt{18} - 3 \sqrt{2} ) {}^{2} - (2 \sqrt{10} - \sqrt{250} ) {}^{2} \\ = (3 \sqrt{2} - 3 \sqrt{2} ) {}^{2} - (2 \sqrt{10} - 5 \sqrt{10} ) {}^{2} \\ = 0 {}^{2} - ( - 3 \sqrt{10} ) {}^{2} \\= 0 - ( - 3 \sqrt{10} ) {}^{2} \\ =( - 3 {}^{2}) \times \sqrt{10} {}^{2} \\ = - 9 \times 10 = - 90[/tex]
Sper ca te-am ajutat!