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

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

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

$x=21$

$Brandon \ is \ now \ 21 \ years \ old. \ Michael \ is \ now \ 33 \ years \ old.$

  !

thanks for all the help guys :P