[tex](( - 5) {}^{2} ) {}^{3} = > ( + 25) {}^{3} = > 15.625 \\ ( - 21) {}^{2} \div ( + 7) {}^{2} = > 441 \div 49 = 9 \\ ( - 15) {}^{3} \div ( + 5) {}^{3} = > ( - 3375) \div ( + 125) =27[/tex]