Question

The daily cost for baking X loaves of bread at Marian’s Bakeryis given in dollars by C=0.8x+ Square root 5x+7000. If bread at Martians Bakery sells for $1.00 a loaf, how many loaves must Marian sell to make a profit ?

Answer 1

Let x denote the number of muffins Marian sells in a day to at least make a profit.
So $1.00 × x will be the amount of revenue Marian earns from selling bread (don't mix revenue with profit. Profit = Revenue - Cost)
In order for Marian to make a profit, revenue must be greater than cost in a day.
$1x > 0.8x + (square root)[5x + 7000]
x > 0.8x + (square root)[5x + 7000]
{ ">" this sign is saying "more than" }
0.2x > (square root)[5x + 7000]
{square both sides}
0.04x > 5x + 7000
-4.96x > 7000
4.96x < 7000
x < 7000 ÷ 4.96

Hope this helps you solve! :) So sorry for my wrong judgement earlier..