Built-up area

John build-up area 4.3 x 6.3 = 27.09 m2 with building with a wall thickness 25 cm. How many centimeters would he have to subtract from the thickness of the walls that the built-up area fell by 5%?

Final Answer:

x =  6.4681 cm

Step-by-step explanation:

a=4.3 m b=6.3 m  S1=a b=4.3 6.3=1002709=27.09 m2 r=100%5%=11005=0.95 S2=r S1=0.95 27.09=25.7355 m2  (a2x) (b2x)=S2  (4.32x) (6.32x)=25.7355 4x221.2x+1.355=0  a=4;b=21.2;c=1.355 D=b24ac=21.22441.355=427.768 D>0  x1,2=2ab±D=821.2±427.77 x1,2=2.65±2.585319 x1=5.235319129 x2=0.064680871 0<x<h  x=x2 cm=x2 100  cm=0.0647 100  cm=6.468 cm=6.4681 cm

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algebraarithmeticplanimetrybasic operations and conceptsUnits of physical quantitiesGrade of the word problem

 
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