Вправи 888 - 1000 » 922 (в-г)

в) 4/(3+ x) = 〖3-4x〗^2/(x^2-9) – 5/(x-3); 〖3-4x〗^2/((x-3)(x+3)) – 5/(x-3) – 4/(x+3) = 0; (3-4x^2-5(x+3)-4(x-3))/((x-3)(x+3)) = 0; (3- 〖4x〗^2-5x-15-4x+12)/((x-3)(x+3)) = 0; (〖-4x〗^2-9x)/((x-3)(x+3)) = 0; –x(4x + 9) = 0, x = 0, x = –9/4 (x – 3)(x + 3) ≠ 0; x ≠ 3, x ≠ –3. Відповідь: 0; –21/4. г) (5(x+2))/(x^2+6x+9) + 1/(x+3) = 1, x ≠ –3; (5x+10)/〖(x+3)〗^2 + (x+3)/〖(x+3)〗^2 = 1; (6x+13)/〖(x+3)〗^2 = 1; 6x + 13 = (x + 3)2; x2 + 6x + 9 – 6x = 13; x2 = 13 – 9; x2 = 4; x = ±2. Відповідь: –2; 2.