Mathematics
jackyd47
2015-11-07 08:04:42
A rectangle has a length of 9.00 inches and a width of 4.25 inches. What is the area in square inches. Round to the correct significant digits
ANSWERS
Ethelene941
2015-11-07 12:56:14

Let the length of a rectangle be l and the width of that rectangle be w, then the area of the rectangle is given by:                            [latex]A_{rectangle}=lcdot w[/latex] In our problem, l= 9 inches, and w=4.25 inches. then,  [latex]A_{rectangle}=lcdot w=9 cdot 4.25=9cdot(4+0.25)=9cdot4+9cdot0.25\\=36+2.25=38.25[/latex] (square inches) -------------------------------------------------------------------------------------------------- Remark: we performed the following operation to make the multiplication easier: [latex]9 cdot 4.25=9cdot(4+0.25)=9cdot4+9cdot0.25[/latex] we wrote 4.25 as 4+0.25, and multiplied 9 to each of these separately, instead of multiplying 9 to 4.25 directly, using the distributive property thus making the operation a little easier. ----------------------------------------------------------------------------------------------------  Answer: 38.25 square inches Remark :  Asking "Round to the correct significant digits" is not correct.  The number of significant digits must be stated.  if we want the number rounded to 3 significant digits 38.25 is 38.6  if we want the number rounded to 2 significant digits 38.25 is 38.0  if we want the number rounded to 1 significant digits 38.25 is 40,0  

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