Question 1162073
.
<pre>

Let x be the amount she had at the start.


After buying the TV, the remainder is  (x-180)  dollars.


{{{3/10}}}  of this remainder, i.e.   0.3*(x-180)  dollars, was spent for a new printer.


The new remainder is  0.7*(x-180).


It is equal to  {{{2/5}}}x = 0.4x.


So, your equation is


    0.4x = 0.7*(x-180).


Simplify ans solve


    0.4x = 0.7x - 0.7*180

    0.7*180 = 0.7x - 0.4x

    0.7*180 = 0.3x

    x = {{{(0.7*180)/0.3}}} = {{{(7*180)/3}}} = 7*60 = 420.


<U>ANSWER</U>.  She had 420 dollars at the start.
</pre>