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# 12:8:4 = 39:A:B what is A and B

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12:8:4 = 39:A:B what is A and B

Guest Jun 9, 2015

#2
+20598
+5

12:8:4 = 39:A:B what is A and B

$$\\\small{\text{ \begin{array}{rclcrcl} 12\cdot \frac{8}{12} &=& 8 &\rm{~~or~~}& 12\cdot \mathbf{\frac{2}{3}} &=& 8\\\\ && &\rm{~~so~~}& 39\cdot \mathbf{\frac{2}{3}} &=& A\\\\ &&&&{A}&{=}& {26}\\\\ \hline &\\ 8\cdot \frac{4}{8} &=& 4 &\rm{~~or~~}& 8\cdot \mathbf{\frac{1}{2}} &=& 4\\\\ && &\rm{~~so~~}& A\cdot \mathbf{\frac{1}{2}} &=& B\\\\ &&&& 26\cdot \mathbf{\frac{1}{2}} &=& B\\\\ &&&&{B}&{=}& {13} \end{array} }}$$

heureka  Jun 9, 2015
#1
+92596
+5

8 is 2/3 of 12.....so A is 2/3 of 39 = 26

4 is 1/3 of 12 .......so  B = 1/3 of 39 = 13

CPhill  Jun 9, 2015
#2
+20598
+5
$$\\\small{\text{ \begin{array}{rclcrcl} 12\cdot \frac{8}{12} &=& 8 &\rm{~~or~~}& 12\cdot \mathbf{\frac{2}{3}} &=& 8\\\\ && &\rm{~~so~~}& 39\cdot \mathbf{\frac{2}{3}} &=& A\\\\ &&&&{A}&{=}& {26}\\\\ \hline &\\ 8\cdot \frac{4}{8} &=& 4 &\rm{~~or~~}& 8\cdot \mathbf{\frac{1}{2}} &=& 4\\\\ && &\rm{~~so~~}& A\cdot \mathbf{\frac{1}{2}} &=& B\\\\ &&&& 26\cdot \mathbf{\frac{1}{2}} &=& B\\\\ &&&&{B}&{=}& {13} \end{array} }}$$