你好！
（1）4x² - 16x + 15 = 0
解：x² - 4x + 15/4 = 0
x² - 4x + 4 = 1/4
(x - 2)² = 1/4
x - 2 = ± 1/2
x₁ = 5/2 ，x₂ = 3/2
（2）9 - x² = 2x² - 6x
解：3x² - 6x - 9 = 0
x² - 2x - 3 = 0
(x+1) (x - 3) = 0
x₁ = - 1，x₂ = 3
（3）(x+1)(2 - x) = 1
解：- x² + x + 2 = 1
x² - x - 1 = 0
x² - x + 1/4 = 5/4
(x - 1/2)² = 5/4
x - 1/2 = ±√5 /2
x₁ = (1+√5)/2 ，x₂ = (1 - √5)/2
(1) 4(x-2)^2=1;
(2) 化简 3x^2-2x-9=0 即x^2-2x-3=0 (x-3)(x+1)=0;
(3) 展开 化简 x^2-x-1=0; 用配方 (x-1/2)^2=5/4
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024