(100-2x)(50-x)=3600

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(100-2x)(50-x)=3600(100-2x)(50-x)=3600(100-2x)(50-x)=3600(100-2x)(50-x)=3600去括号得5000-200x+2x^2=3600则

(100-2x)(50-x)=3600
(100-2x)(50-x)=3600

(100-2x)(50-x)=3600
(100-2x)(50-x)=3600
去括号得
5000-200x+2x^2=3600
则2x^2-200x-1400=0
x^2-100x-700=0
(x-50)^2=3200
x-50=±40√2
则x=50+40√2或x=50-40√2

(100-2x)(50-2x)=3600
(50-x)(25-x)=900
1250-75x+x²=900
x²-75x+350=0
x=[75±√(75²-4*350)]/2=(75±65)/2
所以x=5或x=70
原方程整理得:5000-100x-200x+4x²=3600
两边同除以2得:2...

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(100-2x)(50-2x)=3600
(50-x)(25-x)=900
1250-75x+x²=900
x²-75x+350=0
x=[75±√(75²-4*350)]/2=(75±65)/2
所以x=5或x=70
原方程整理得:5000-100x-200x+4x²=3600
两边同除以2得:2500-50x-100x+2x²=1800
移项得:2x²-50x-100x+2500-1800=0
合并同类项得:2x²-150x+700=0
两边同除以2得:x²-75x+350=0
左边分解因式得:(x-70)(x-5)=0
x-70=0或x-5=0
解得x=70或x=5

收起

100*50 -100x-100x+2x^2 = 3600

2x^2 -200x+1400 = 0

x^2-100x+700=0

结果 50 加减 30倍根号2