Step-by-step explanation:

If 81=n-3(-5+4n)
81= n+15-12n
81= -11n+15
-11n=81-15
-11n=66
n=-6
First of all lets find the area of the rectangle.
13 ft × 12 ft = 156 square feet.
Now lets find the price which is $8 / square foot. Using proportions we get:
$8/sq ft × 156 sq ft. Simplifying we get
$8 × 156 = $1248.
The wallpaper will cost $1248
Answer:

Step-by-step explanation:
we know that
In a parallelogram opposite sides are equal and parallel
The figure FHJM is a parallelogram
so


therefore

Answer:
25
Step-by-step explanation:
Given the model:
y=−3.5x+400
Number of children in amusement park = y
Temperature = x
On a certain day:
Temperature = 90°F
Number of children in park = 60
Using the model :
The predicted number of children in park when temperature is 90°F would be :
y = - 3.5(90) + 400
y = - 315 + 400
y = 85
Model prediction = 85 children
Actual figure = 60
Residual :
|Actual - predicted | = |60 - 85| = 25 children