Вопрос пользователя:
Решите уравнение:
(x+6)/(x-6) * (x-4)^2/(x+4)^2 + (x-6)/(x+6) * (x+9)^2/(x-9)^2 = 2* (x^2+36)/(x^2-36)
Илюха отвечает:
(x+6)/(x-6) * (x-4)^2/(x+4)^2 + (x-6)/(x+6) * (x+9)^2/(x-9)^2 = 2* (x^2+36)/(x^2-36)
((x+6)(x-4)^2)/((x-6)(x+4)^2) + ((x-6)(x+9)^2)/((x+6)(x-9)^2=2*(x^2+36)/(x^2-36)
((x+6)^2(x-4)^2(x-9)^2)/((x-6)(x+4)^2(x+6)(x-9)^2) +
+((x-6)^2(x+9)^2(x+4)^2)/((x+6)(x-9)^2(x-6)(x+4)^2)=2*(x^2+36)/(x^2-36)
((x^2+12x+36)(x^2-8x+16)(x^2-18x+81) +(x^2-12x+36)(x^2+18x+81)(x^2+8x+16))/
/((x-6)(x+4^2(x+6)(x-9)^2) =2*(x^2+36)/(x^2-36)
((x^6-18x^5+4x^5-72x^4+81x^4+44x^4+792x^3+324x^3-96x^3+576x^2-3564x^2+1728x^2-10368x-7776x+46656)+(x^6+8x^5+6x^5+48x^4+16x^4-99x^4-792x^3+96x^3-324x^3+2916x^2-1584x^2-2592x^2+23328x-5184x+46656))/((x-6)(x+4)^2(x+6)(x-9)^2) =2*(x^2+36)/(x^2-36)
((2x^6-70x^4-2520x^2+93312))/((x-6)(x+4)^2(x+6)(x-9)^2) =2*(x^2+36)/(x^2-36)
(x^2+36)((2x^4-142x^2+2592)/((x-6)(x+4)^2(x+6)(x-9)^2)-2*(x^2+36)/(x^2-36))=0
а) x^2+36=0 => x^2=-36 – нет решений
б) ((2x^4-142x^2+2592)/((x-6)(x+4)^2(x+6)(x-9)^2)-2*(x^2+36)/(x^2-36))=0
((2x^4-142x^2+2592)-2(x+4)^2(x-9)^2)/((x-6)(x+4)^2(x+6)(x-9)^2)=0
((2x^4-142x^2+2592)-2(x+4)^2(x-9)^2)=0
2x^4-2x^4+20x^3+94x^2+142x^2-720x-2592+2592=0
20x^3-48x^2-720x=0
x*(5x^2-12x-180)=0
1) x=0
2) 5x^2-12x-180=0
D=3744
X1=(6-sqrt(936))/5
x2=(6+sqrt(936))/5