Question

WILL MARK BRAINLIEST! PLEASE HELP MEH!Use the relationship between the angles in the figure to answer the question. Which equation can be used to find the value of x? Drag and drop the equation into the box.
A) x=180−31+40
B)x=90−40
C)​​x=180−(31+40)
D)​​x=90−(31+40)

Answer 1

A straight line (or two rays in a  straight line) = 180o
to find x start with this equation
31 + x + 40 = 180 Now get all the numbers on the right.
(31 + 40) + x = 180
x = 180 - (31 + 40)
Only A or C can be correct. It is C, but you have to be very careful how you eliminate A
C <<<< answer.


x = 180 - 31 - 40 is the correct way to remove the brackets. 
x = 180 -  71
x = 109

There are better ways to do this particular question without using brackets.

Answer 2

Answer:

C. $x=180^o-(31^o+40^o)$  

Step-by-step explanation:

We have been given a figure of angles formed on a straight line.

Since we know that the angles on a straight line add up-to 180 degrees. Upon using this property we can set an equation as:

$31^o+x^o+40^o=180^o$

Let us subtract 40 and 31 degrees from both sides of our equation to solve to x.

$31^o-31^o+x^o+40^o-40^o=180^o-31^o-40^o$    

$x=180^o-31^o-40^o$

Upon factoring negative sign from right side of our equation we will get,

$x=180^o-(31^o+40^o)$

Therefore, the equation $x=180^o-(31^o+40^o)$ can be used to find the value of x and option C is the correct choice.