Answer:
50
Step-by-step explanation:
5x=25
Because negative 3y and positive 3y got cancelled
Greetings!
"<span>What is the general process for solving an equation with one variable?"...
Typically when solving an equation with one variable, your objective is to
isolate the variable on one side of the equation. This can be done adding/subtracting number to cancel them out on one side. You can also multiply/divide coefficients in order to isolate a variable.
Example:</span>

<span>Add
-4 to both sides to isolate the variable.
</span>

<span>
Simplify.
</span>

Divide both sides by
2 to isolate the variable on one side.


Hope this helps.
-Benjamin
The wall area is the product of the room perimeter and the room height:
A₁ = (2*(12.5 ft + 10.5 ft))*(8.0 ft) = 368 ft²
The window and door area together is
A₂ = 2*((4 ft)*(3 ft)) + (7 ft)*(3 ft) = 45 ft²
The area of one roll of wallpaper is
A₃ = (2.5 ft)*(30 ft) = 75 ft²
Then the number of rolls of wallpaper required will be
1.1*(A₁ - A₂)/A₃ ≈ 4.74
5 rolls of wallpaper should be purchased.
_____
As a practical matter, not much of the window and door area can be saved. The rolls are 30 inches wide, but the openings are 36 inches wide. Some will likely have to be cut from two strips. The strips will have to be the full length of the wall, and the amount cut likely cannot be used elsewhere. If the window and door area cannot be salvaged, then likely ceiling(5.4) = 6 rolls will be needed (still allowing 10% for matching and waste).