The unknown number is n. So n is the unknown variable in the equation.
In order to write an equation in which n is included we must know some dependence of n with other values.
We know that <span>the difference of three times a number and 44 is −19. So, we can write:
3*n-44=-19
3*n=-19+44
3*n=25
n=25/3
</span>
We will need like a graph for that
The first thing you should do is calculate how many pounds of cheese a hamburger has
1 hamburger = 1/4 pound of cheese.
Then, you can make a rule of three to know how many pounds of cheese were sold:
1 ---> 1/4
310 ---> x
Clearing x we have:
x = ((310) / (1)) * (1/4) = 77.5
Answer
they sell last saturday 77.5 pounds of cheese