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math-quadraticequationsArectangularbuildingthatmeasures100mby80mistobesurroundedbyalawnofuniformwidth.Theareaofthelawnmustequaltheareaofthebuilding.Findthewidthofthelawn,tothenearesttenthofametre.Pleasep
题目详情
math - quadratic equations
A rectangular building that measures 100m by 80m is to be surrounded by a lawn of uniform width. The area of the lawn must equal the area of the building. Find the width of the lawn, to the nearest tenth of a metre.
Please provide a clear step by step explanation and show calculations! Thank you!
A rectangular building that measures 100m by 80m is to be surrounded by a lawn of uniform width. The area of the lawn must equal the area of the building. Find the width of the lawn, to the nearest tenth of a metre.
Please provide a clear step by step explanation and show calculations! Thank you!
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答案和解析
这个问题你画个图就清楚了
建筑的地面是个矩形,而且草坪均匀的环绕房子
所以我们可以设草坪的宽度为x
得到方程：
4x²+2*100x+2*80x=100*80
x²+90x-2000=0
用求根公式吧~
建筑的地面是个矩形,而且草坪均匀的环绕房子
所以我们可以设草坪的宽度为x
得到方程：
4x²+2*100x+2*80x=100*80
x²+90x-2000=0
用求根公式吧~
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