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 ?

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..

Number nine is f(x)= 40x : ) hoped i ya