Here’s the first few and you can do the rest with the same principles. If you need more help with the last ones then let me know
Combinations of 7 taken 4 at a time.
C (7,4) = 7! /[ 4!(3!)]
7 x 6 x 5 = 210
210 divided by 3 = 70
70 divided by 2 = 35
Answer:



Step-by-step explanation:
Required
Which equals 

Collect like terms


Divide both sides by 2


Collect like terms


Divide both sides by 2


Collect like terms


Divide both sides by -2


Divide both sides by 2

Collect like terms



Divide both sides by 2

Collect like terms


Hence, the equations with the required solution are:



Answer:
B.
Step-by-step explanation:
You have to use the number in the variable to figure out if the number multiplied by 3.5 goes over 20 dollars. The highest you can go without going over 20 dollars is 5 notebooks
You can download the answer here:
bit. ly/3a8Nt8n