Вправи 301 - 400 » 394

394. Спростіть вираз: 1) 1/y^2 – y–2 = 1/y^2 – 1/y^2 = 0; 2) (a + 10)–1 + 9/(a+10) = 1/(a+10) + 9/(a+10) = 10/(a+10); 3) a(a + 4)–1 + 4(a + 4)–1 = a/(a+4) + 4/(a+4) = (a+4)/(a+4) = 1; 4) 7/(7+n ) + n(7 + n)–1 = 7/(7+n) + n/(7+n) = (7+n)/(7+n) = 1; 5) (m + n)–1 – (m + n)0 = 1/(m+n) – 1\m+n = (1-m-n)/(m+n); 6) (4 + x)–1 – (4 – x)–1 = 1^(\4-x)/(4+x) – 1^(\4+x)/(4-x) = (4-x-4-x)/((4+x)(4-x)) = –2x/〖16-x〗^2 = 2x/(x^2- 16).