Answer:
3n^2+9+5n^4+55n
Step-by-step explanation:
Steps
$\left(3n^2+9+5n^4-3n\right)+\left(-9n\left(-7\right)-5n\right)$
$\mathrm{Remove\:parentheses}:\quad\left(a\right)=a,\:-\left(-a\right)=a$
$=3n^2+9+5n^4-3n+9n\cdot\:7-5n$
$\mathrm{Add\:similar\:elements:}\:-3n-5n=-8n$
$=3n^2+9+5n^4-8n+9\cdot\:7n$
$\mathrm{Multiply\:the\:numbers:}\:9\cdot\:7=63$
$=3n^2+9+5n^4-8n+63n$
$\mathrm{Add\:similar\:elements:}\:-8n+63n=55n$
$=3n^2+9+5n^4+55n$
The scale 1:35 indicates that for every 1 meter on the scale model, there are really 35 meters in real life.
So if the scale model is 6.6 meters, you would do 35 * 6.6 to find the length in real life, which is 231 meters.
The answer is 231 meters.
To find the cost of each folder first:
30/82.50 = 1/x
cross multiply:
30x = 82.50
find x.
x = 2.75
a journal is 10 times as much as a folder.
multiply.
2.75*10=27.50
