solve:
(1/(x-10)+(1/20)=(1/(20(x^2-100))
1/(x-10) + 1/20 = 1/[20(x-10)(x+10)]
put all over a common denominator
20(x-10)(x+10)
20(x+10) + (x-10)(x+10) = 1
20x + 200 + x^2 - 100 = 1
x^2 + 20x +99 = 0
(x+9)(x+11) = 0
x = -9 or -11
(1/(x-10)+(1/20)=(1/(20(x^2-100))
put all over a common denominator
20(x-10)(x+10)
20(x+10) + (x-10)(x+10) = 1
20x + 200 + x^2 - 100 = 1
x^2 + 20x +99 = 0
(x+9)(x+11) = 0
x = -9 or -11