There is : 3 pencils
4 Bubble gums
2 sports cards
In each favor bag
We can start by getting rid of parenthesis:
4x-3x+6=21
Then we can combine like terms:
x=21-6
x=15
So our end product is x=15.
Hope I helped soz if I'm wrong ouo.
~Potato.
Copyright Potato 2019.
Answer: 
Work Shown:

This can be rewritten into 
Answer:
b = √(c^2 - a²)
Step-by-step explanation:
Start with the given c = √a^2 + b^2. Squaring both sides, we get:
c² = a² + b².
We want to iosolate b² and then b.
So: subtract a² from both sides, resulting in:
c² - a² = b²
Taking the square root of both sides, we get:
√b² = √(c² - a²)
and so:
b = √(c^2 - a²)
Answer:
Ab^2 = CA^2 + BC^2
8^2 = 6^2 + a^2
64 = 36 + a^2
64-36 = a^2
28 = a^2
square root of 28 = square root of a^2
5 ,29 = a
5 = a