Question 874915
Simple linear system, two variables.
x, price of cheap
y, price of high priced


9x+7y=19.7
and
3x+5y=19.825


Solve whatever way you want.  You could try multiplying the second equation by 3, and use this to eliminate x, and then solve for y...
{{{3(3x+5y)-9x-7y=3(19.825)-19.7}}}, as a start,...