11 pangkat x²-x =121 pangkat x+20????

11^(x² - x) = 121^(x + 10)
11^(x² - x) = (11^2)^(x + 10)
11^(x² - x) = 11^(2(x + 10)
x² - x = 2x + 20
x² - x - 2x - 20 = 0
x² - 3x - 20 = 0

rumus abc :
x² - 3x - 20 = 0
a = 1
b = -3
c = -20

x1.2 = (-b ± √(b² - 4ac))/(2a)
x1.2 = (3 ± √(9 - (-80)))/2
x1.2 = (3 ± √89)/2

Jadi, nilai x yg memenuhi :
x1 = (3 + √89)/2
x2 = (3 - √89)/2