45x & # 10135; (x - 0.8) = 50 방정식

45x & # 10135; (x - 0.8) = 50 방정식

45x & # 10135; (x - 0.8) = 50
9x (x - 0.8) = 10
9x ^ 2 - 7.2x = 10
x ^ 2 - 0.8x = 10 / 9
(x - 0.4) ^ 2 = 10 / 9 + 0.16 = 11.44 / 9
x - 0.4 = ± √ 11.44 / 3
x1 = 0.4 + 체크 11.44 x2 = 0.4 - 체크 11.44.