Answer:
D. 
Step-by-step explanation:
First, move the variable (+ 2y) to the left-hand side and change its sign.

Then, move the constant (+ 7) to the right-hand side and change its sign.

Then, collect the like terms (y - 2y)

Finally, add the numbers (3 + 7). That will get you your final answer.

Answer:
11
Step-by-step explanation:
Answer:
Thy bought 150 Sweatshirts (x) and 250 tshirts (y)
Step-by-step explanation:
35x + 25y = 11500
x + y = 400
-25 (x + y = 400) Multiply by -25 to get the y's to disappear when you add the two equations together
-25x - 25y = 10000
<u> 35x + 25y = 11500 </u>
10x =1500
x = 150
Plug 150 in either equation for x to find y
150 + y = 400
y = 250
Answer:

What is given to you is interval notation. We have the interval start at 0 and end at 8. The value 0 is not included in the interval as indicated by the parenthesis. So we go with a "less than" sign (instead of a "less than or equal to" sign)
The value 8 is included since a square bracket is used here. The use of "or equal to" is needed to make sure the endpoint 8 is included.
So x can be any number between 0 and 8. It can't be 0 but it can be 8.
What is the question? Please specific!