Simplify: (3n2 +9+5n4 – 3n)+(-9n* - 7 -5n?)

3n^2+9+5n^4+55n

Step-by-step explanation:

Steps

$\left(3n^2+9+5n^4-3n\right)+\left(-9n\left(-7\right)-5n\right)$

$\mathrm{Remove\:parentheses}:\quad\left(a\right)=a,\:-\left(-a\right)=a$

$=3n^2+9+5n^4-3n+9n\cdot\:7-5n$

$\mathrm{Add\:similar\:elements:}\:-3n-5n=-8n$

$=3n^2+9+5n^4-8n+9\cdot\:7n$

$\mathrm{Multiply\:the\:numbers:}\:9\cdot\:7=63$

$=3n^2+9+5n^4-8n+63n$

$\mathrm{Add\:similar\:elements:}\:-8n+63n=55n$

$=3n^2+9+5n^4+55n$

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!