Question 174700
let x be the number of bottles purchased per month by Maxwell...let C=total cost of bottles purchased
:
{{{x>=30}}}
:
3x+25=C....cost from supplier....eq 1
4x+ 5=C....cost from competitor..eq 2
:
since {{{x>=30}}}...we will use 30 as the number of bottles purchased
:
3(30)+25=115....Cost of supplier
4(30)+5=125.....Cost of competitor.
:
The cost of the competitor will only continue to be higher per bottle purchased therefore I would tell Maxwell to continue to use his supplier.
:
side note ..make an inequality statment showing at what number of bottles bought that the suppliers pricing is equal to or better than the competitors:
{{{3x+25>=4x+5}}}subtract 3x and 5 from each side.
:
x>=20....meaning that the competitors pricing is better or equal up to 20 purchased bottles.  Anything greater than 20 and suppliers pricing is better