Answer:
√
53
Step-by-step explanation:
All you have to do is plug in the x and y values for each ordered pair into the left hand side of the equation and see if you get 15 = 15. If you do, the ordered pair is a solution; otherwise it is not a solution. For example, let's try (-2,-3); that is x = -2 and y = -3:
2x - 9y = 15
2(-2) - 9(-3) = 15
-4 - (-27) = 15
-4 + 27 = 15
23 = 15
This is obviously not true, so (-2,-3) is not a solution. Now you try it on each of the ordered pairs given in the problem statement.
So all of the internal angles of a triangle will add up to 180 degrees. So if we add all of the expressions given and set them equal to 180, we can solve for x, then solve for each angle...
(2x + 1) + (3x - 3) + 9x = 180
2x + 3x + 9x + 1 - 3 = 180
14x - 2 = 180
14x = 182
x = 13
Now we can substitute 13 into each expression to find the value of each angle...
2x + 1 =
2(13) + 1 =
26 + 1 = 27 degrees
3x - 3 =
3(13) - 3 =
39 - 3 = 36 degrees
9x =
9(13) = 117 degrees
So the 3 angles are 27 degrees, 36 degrees, and 117 degrees.
The smallest is 27 degrees
** Note-- I don't see 27 degrees in the answer choices you gave, so I double checked my math (I didn't find any mistakes). Please check to see that the question is written correctly (pay close attention to plus and minus signs).
-7(4-2)+1=15-7x
-7 x 2 + 1 = 15 - 7x
-14 + 1 = 15 -7x
-13 -15= -7x
-28 = -7x
-28 / -7 = x
x=4
3x - 54 = 160 >I just flipped the equation
3x - 54 (+54) = 160 (+54) added 54 each
3x = 160
3x/3 = 160/3 >divided 3 to each side
x = 160/30
or 53.33333333333333333~