Question 1119335
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<pre>
From 

2x + 3y = 12  you have (by squaring both sides)


{{{4x^2 + 2*(2x)*(3y) + 9y^2}}} = 144.


Now replace  xy in the last formula by 6 (as it is given !) to get


{{{4x^2 + 2*2*3*6 + 9y^2}}} = 144,


{{{4x^2 + 9y^2}}} = 144 - 2*2*3*6 = 72.


It is your 


<U>Answer</U>.  {{{4x^2 + 9y^2}}} = 72.
</pre>

Solved.


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To write  x_squared,   &nbsp;write  &nbsp;x^2.   &nbsp;&nbsp;Find the symbol  &nbsp;" ^ "&nbsp; in your keyboard, &nbsp;where the button &nbsp;(digit) &nbsp;"6" is, &nbsp;in the upper register.