Вправи 1001 - 1100 » 1086

1086. Розклади на множники тричлен: а) 0,2n2 + 0,8n – 12 = 0,2(n2 + 4n – 60) = 0,2(n + 10)(n – 6); n1 = –10; n2 = 6; б) 4/49x2 + 15/7x + 9 = (2/7x)2 + 2 • 2/7x • 3 + 32 = (2/7x + 3)2; 2/7x + 3 = 0; 2/7x = –3; x = –3 : 2/7; x = –10,5; в) m2 – 3√2m + 4 = (m – (√2+ √6)/2)(m + (√2- √6)/2); m = (√2 ± √(2+4))/2 = (√2 ± √6)/2; m1 = (√2+ √6)/2; m2 = (√2- √6)/2.