Answer:

Step-by-step explanation:
So we have the equation (I'm assuming the brackets are synonymous with parentheses):

Distribute the left:

Add 15 to both sides:

Subtract 2w from both sides:

And we're done!
Edit: Typo
Answer:
15 boys
Step-by-step explanation:
start by dividing 20 by 4
you get 5
5 times 3 next
now you have 15
Answer:
The exact value of 
Step-by-step explanation:
we know that
The angle
belong to the fourth quadrant
The function cosine is positive in the first and in the fourth quadrant
so

Remember that

so

300.75 you need to find the length, width, and height. then multiple everything together and then by 2