Question 982901


Let &nbsp;<B>x</B>&nbsp; be the Maggie's age and &nbsp;<B>y</B>&nbsp; be her brother's age. 


Then you have two equations:


1. &nbsp;y = 2x -3, &nbsp;&nbsp;and 


2. &nbsp;x + y = 24.


So, &nbsp;you need to solve the system of two linear equations in two unknowns 


{{{system(y = 2x - 3,
x + y = 24)}}}. 


Express &nbsp;<B>y</B>&nbsp; from the second equation &nbsp;y = 24 - x&nbsp; and substitute it into the first equation. &nbsp;You will get


24 - x = 2x - 3.


Simplify it step by step:


24 + 3 = 2x + x,


27 = 3x,


x = {{{27/3}}} = 9.


<B>Answer</B>. &nbsp;Maggie is &nbsp;9&nbsp; years old.