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The areas of two similar rectangles add up to 39 square units. Twice the area of Rectangle A plus one-third the area of Rectangle B equals 33 square units. What are the areas of Rectangles A and B?   

 

Thank you guys for helping me, math is not my favorite subject… 

 Feb 26, 2015

Best Answer 

 #1
avatar+129852 
+8

Call x the area of A and y the area of B

And we know that

x + y = 39

And that

2x + (1/3)y = 33

Using the first equation, we have that  y = 39 - x   and subbing for y in the second, we have

2x + (1/3)(39 - x)  = 33  simplify

2x + 13 - (1/3)x = 33   multiply through by 3 to clear the fraction

6x + 39 - x  = 99

5x + 39 = 99 subtract 39 from both sides

5x = 60     divide by 5 on both sides

x =  12 sq units     this is the area of A

And 39 - 12  = 27 sq units ....  is the area of B

 

 Feb 26, 2015
 #1
avatar+129852 
+8
Best Answer

Call x the area of A and y the area of B

And we know that

x + y = 39

And that

2x + (1/3)y = 33

Using the first equation, we have that  y = 39 - x   and subbing for y in the second, we have

2x + (1/3)(39 - x)  = 33  simplify

2x + 13 - (1/3)x = 33   multiply through by 3 to clear the fraction

6x + 39 - x  = 99

5x + 39 = 99 subtract 39 from both sides

5x = 60     divide by 5 on both sides

x =  12 sq units     this is the area of A

And 39 - 12  = 27 sq units ....  is the area of B

 

CPhill Feb 26, 2015

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