Answer:
Cost of one roll of plain wrapping: 
Cost of one roll of holiday wrapping paper: 
Step-by-step explanation:
Let be "p" the cost in dollars of one roll of plain wrapping paper and "h" the cost in dollars of one roll of holiday wrapping paper.
Based on the information given, we can set up this system of equations:

In order to solve it, we can use the Substitution method. The steps are:
1. Solve for "p" from the first equation:

2. Substitute the above into the second equation and solve for "h":
3. Substitute the value of "h" into
:

Answer:
10y
solve. you need to combine like terms and subtract.
<u>1) Rewrite it in the form a^2-2ab+b^2, where a=11m and b=9</u>
(11m)^2-2(11m)(9)+9^2
<u>2) Use Square of Difference: (a-b)^2=a^2-2ab+b^2</u>
(11m-9)^2
<u>Your answer is (11m-9)^2</u>
X=9. x=-15. you also have to turn the 24 into a negative and solve the equation