Answer: 
Step-by-step explanation:
To solve this exercise you need to remember the following:
→ 
Therefore, keeping the above on mind, you can solve for x as following:


Remember that, by definition:
, then you have:

Subtract 6 from both sides of the equation.
Then the value of x is:

Answer:
i think you'll need 1 foot 6 inches of wood
Step-by-step explanation:
Answer:
x = 20
y = 100
Step-by-step explanation:
To figure out x do this.
3x + 2x = 7x - 40 (collect like terms)
5x = 7x -40 (subtract 7x on both sides)
-2x = -40 (divide by -2 on both sides)
x = 20
Plug in to get y
Since 7x - 40 and y are vertical they equal the same amount
7(20) - 40 = y (multiply 7 by 20)
140 - 40 = y (collect like terms)
100 = y
Hope this helps ya! Keep smiling!