n = 21
x2 = -14/18
Пошаговое объяснение:
9*3^2 - 20*3 - n = 0
81 - 60 - n = 0
n = 81 - 60 = 21
9x^2 - 20x - 21 = 0
D = 20^2 - 4*9*(-21) = 1156 = 34^2
x1 = (20 + 34)/(2*9) = 3
x2 = (20 - 34)/(2*9) = -14/18
n = 21
x2 = -14/18
Пошаговое объяснение:
9*3^2 - 20*3 - n = 0
81 - 60 - n = 0
n = 81 - 60 = 21
9x^2 - 20x - 21 = 0
D = 20^2 - 4*9*(-21) = 1156 = 34^2
x1 = (20 + 34)/(2*9) = 3
x2 = (20 - 34)/(2*9) = -14/18