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Michael is 12 years older than Brandon. Seventeen years ago, Michael was 4 times as old as Brandon.

How old is Brandon now? can somebody help me through this step by step thank you D:

BentoBot  May 5, 2017

Best Answer 

 #1
avatar+18767 
+3

Michael is 12 years older than Brandon. Seventeen years ago,

Michael was 4 times as old as Brandon.

How old is Brandon now?


Let m = Michael
Let b = Brandon

 

\(\begin{array}{|lrcll|} \hline (1) & m &=& b+12 \\\\ (2) & m-17 &=& 4\cdot (b-17) \quad & | \quad m=b+12 \\ & b+12-17 &=& 4\cdot (b-17) \\ & b+5 &=& 4b- 68 \\ & 3b&=& 63 \\ & \mathbf{b} & \mathbf{=} & \mathbf{21} \\\\ (1) & m &=& b+12 \quad & | \quad b=21 \\ & m &=& 21+12 \\ & \mathbf{m} & \mathbf{=} & \mathbf{33} \\ \hline \end{array} \)

 

Michael is 33 and Brandon is 21

 

laugh

heureka  May 5, 2017
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4+0 Answers

 #1
avatar+18767 
+3
Best Answer

Michael is 12 years older than Brandon. Seventeen years ago,

Michael was 4 times as old as Brandon.

How old is Brandon now?


Let m = Michael
Let b = Brandon

 

\(\begin{array}{|lrcll|} \hline (1) & m &=& b+12 \\\\ (2) & m-17 &=& 4\cdot (b-17) \quad & | \quad m=b+12 \\ & b+12-17 &=& 4\cdot (b-17) \\ & b+5 &=& 4b- 68 \\ & 3b&=& 63 \\ & \mathbf{b} & \mathbf{=} & \mathbf{21} \\\\ (1) & m &=& b+12 \quad & | \quad b=21 \\ & m &=& 21+12 \\ & \mathbf{m} & \mathbf{=} & \mathbf{33} \\ \hline \end{array} \)

 

Michael is 33 and Brandon is 21

 

laugh

heureka  May 5, 2017
 #2
avatar+11 
+2

wow thx so much its clear to me now i just didnt understand the equation process i needed to do (:

BentoBot  May 5, 2017
edited by BentoBot  May 5, 2017
 #3
avatar+7155 
+1

Michael is 12 years older than Brandon. Seventeen years ago, Michael was 4 times as old as Brandon.
How old is Brandon now? can somebody help me through this step by step thank you D:

 

Brandon is now x years old. Michael is now  x + 12 years old.


Then:

 

\(M=x+12\)                            now

\((x-17)\cdot 4=M-17\)         17 years ago . 

\(4x-68=(x+12)-17\)     M=x+12

\(3x=68+12-17\)                - x + 68

3x=63                                         / 3

 

\(x=21\)

 

\(Brandon \ is \ now \ 21 \ years \ old. \ Michael \ is \ now \ 33 \ years \ old.\)

 

laugh  !

asinus  May 5, 2017
 #4
avatar+11 
+1

thanks for all the help guys :P

BentoBot  May 5, 2017

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