I cant really help you out with the last part since setting up the sum of three digits with two variable complicates things but here is the calculation and answer as follows:
let the number be a be represented as xyz (where x is the hundredth digit, y is the tenth digit and z is the one digit)
which means a = 100x+10y+z (equation 1)
if you add the three digits x+y+z = 19 (equation 2)
if you switch positions of the tenth digit and one digit then
a-27 = 100x + 10z +y (equation 3) (number diminish by 27 hence why a -27)
if you switch the position of the hundredth and tenth digit then
a+180 = 100y + 10x + z (equation 4) (number increases by 180)
if you use equation 1, 2, 3, and 4 and solve for x, y and z which gives you a then the number is 685.
Sorry for the long explanation but this was the first approach that came to mind might be more simpler ones and also one that helps you set up the sum of three digits with only 2 variables.
The anwser is 14 because 14-11=3
let x represent the number of cups of additional cups of sugar and y represents the total number of pies she can bake.
Given that;
"Laura has already baked 9 pies, and she can bake 2 pies with each additional cup of sugar she buys"

With 14 additional cups of sugar;

substituting the value of x;

Therefore, the total number of pies Laura can Bake with 14 additional cups of sugar is;
Answer:
$996
Step-by-step explanation:
The rectangular plot has an area that is the product of its length and width. We are given the width as 12 feet, and the area as 240 ft², so we can find the length from ...
... A = L×W
... 240 ft² = L×(12 ft)
... 240 ft²/(12 ft) = L = 20 ft
Opposite sides of the rectangle are the same length, so the cost of fence for a side of a given length will be the sum of the costs of the opposites sides.
The 12 ft side has one segment that is $18 per foot, and one that is $15 per foot. For the 20 ft sides, both are $15 per foot. Then the total cost can be figured from ...
... (12 ft)·($18/ft + $15/ft) + (20 ft)·($15/ft +$15/ft) = 12·$33 +20·$30 = $996
The width could be 6 and the length coupd be 2 or vice versa