因式分解解一元二次方程1.(2x-1)²=(5-x)²2.x²-4x+4=(5-2x)²(同时用配方法、公式法解出)3.(2x+1)(2x+3)=154.(x+5)²-2(x+5)-8=0非常感谢各位!
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 13:24:42
![因式分解解一元二次方程1.(2x-1)²=(5-x)²2.x²-4x+4=(5-2x)²(同时用配方法、公式法解出)3.(2x+1)(2x+3)=154.(x+5)²-2(x+5)-8=0非常感谢各位!](/uploads/image/z/1631050-34-0.jpg?t=%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%E8%A7%A3%E4%B8%80%E5%85%83%E4%BA%8C%E6%AC%A1%E6%96%B9%E7%A8%8B1.%282x-1%29%26sup2%3B%3D%285-x%29%26sup2%3B2.x%26sup2%3B-4x%2B4%3D%285-2x%29%26sup2%3B%28%E5%90%8C%E6%97%B6%E7%94%A8%E9%85%8D%E6%96%B9%E6%B3%95%E3%80%81%E5%85%AC%E5%BC%8F%E6%B3%95%E8%A7%A3%E5%87%BA%293.%282x%2B1%29%282x%2B3%29%3D154.%28x%2B5%29%26sup2%3B-2%28x%2B5%29-8%3D0%E9%9D%9E%E5%B8%B8%E6%84%9F%E8%B0%A2%E5%90%84%E4%BD%8D%21)
因式分解解一元二次方程1.(2x-1)²=(5-x)²2.x²-4x+4=(5-2x)²(同时用配方法、公式法解出)3.(2x+1)(2x+3)=154.(x+5)²-2(x+5)-8=0非常感谢各位!
因式分解解一元二次方程
1.(2x-1)²=(5-x)²
2.x²-4x+4=(5-2x)²(同时用配方法、公式法解出)
3.(2x+1)(2x+3)=15
4.(x+5)²-2(x+5)-8=0
非常感谢各位!
因式分解解一元二次方程1.(2x-1)²=(5-x)²2.x²-4x+4=(5-2x)²(同时用配方法、公式法解出)3.(2x+1)(2x+3)=154.(x+5)²-2(x+5)-8=0非常感谢各位!
1.(2x-1)²=(5-x)²
(2x-1)^2-(5-x)^2=0,
(2x-1+5-x)(2x-1-5+x)=0,
(x+4)(3x-6)=0
x+4=0,3x-6=0,
x1=-4,x2=2,
2.x²-4x+4=(5-2x)²,
配方法
x^2-4x+4=25-20x+4x^2
x^2-4x^2-4x+20x+4-25=0,
-3x^2+16x-21=0,
3x^2-16x+21=0,
x^2-16x/3+7=0,
x^2-16x/3=-7,
x^2-16x/3+64/9=-7+64/9
(x-8/3)^2=1/9,
x-8/3=1/3,x-8/3=-1/3
x1=3,x2=7/3
公式法
x^2-4x+4=25-20x+4x^2
x^2-4x^2-4x+20x+4-25=0,
-3x^2+16x-21=0,
3x^2-16x+21=0,
a=3,b=-16,c=21,
b^2-4ac
=256-252
=4,
x=(16±2)/6
x1=3,x2=7/3
3.(2x+1)(2x+3)=15
4x^2+8x+3=15,
4x^2+8x+3-15=0,
4x^2+8x-12=0,
x^2+2x-3=0
(x+3)(x-1)=0,
x+3=0,x-1=0,
x1=-3,x2=1
4.(x+5)²-2(x+5)-8=0
(x+5-4)(x+5-2)=0,
(x+1)(x+3)=0,
x+1=0,x+3=0,
x=-1,x=-3