<span>There are three undefined terms in geometry. These are points, line, and plane. Among the given choices, there is only one which is not an undefined term and that is ray. Ray is a part of a line that has an enpoint in one side and extends indefinitely on the opposite side. Hence, the answer is the second choice. </span>
Answer:
The simplified expression for the given expression will be:
c. 
Step-by-step explanation:
Given expression:
To simplify the expression.
Solution:
In order to simplify the expression, we will first remove the parenthesis by reversing the signs of the terms inside the parenthesis which lies after a negative sign out side the parenthesis.
<em>This is because negative multiplies to a negative to give a positive and negative multiplies to a positive to give a negative.</em>
So, we have:
⇒ 
Combining like terms
⇒ 
<em>The like terms can be evaluated as</em>
Thus, the simplified expression will be:
⇒
Assuming you mean 2x-8y=7, we can start by multiplying the first equation by -2 and adding it to the second (to cross out the x), resulting in -18y=-5. After that, we can divide both sides by -18, resulting in y=5/18. Next, plugging that into 4x-2y=9, we have 4x-10/18=9. Adding 10/18 to both sides, we get 4x=9+10/18. After that, we can divide both sides by 4, resulting in x=(9+10/18)/4=
Answer:
20
Step-by-step explanation:
→ First find the value of x and y
x + y = 5
x - y = 4
→ Add the equations to cancel out the y's
2x = 9
→ Divide both sides by 2 to find the value of x
x = 4.5
→ Substitute x = 4.5 back into x - y = 4 to find the value of y
4.5 - y = 4
→ Minus 4.5 from both sides to isolate -y
-y = -0.5
→ Multiply everything by -1
y = 0.5
→ Substitute x = 4.5 and y = 0.5 into x² - y²
4.5² - 0.5² = 20.25 - 0.25 = 20
