Which relation is NOT a function?

The relation represented by diagram 4 is NOT a function.

Step-by-step explanation:

To tell if a relation is not a function, pay attention to the x-intercepts. If there is more than one y-intercept with the same x-intercept, then it is not a function, because a function can only have one output (y-value) for each input (x-value).

According to the fourth diagram, the domains include 1, 2, and 3 while the range includes A, B, and C. Also, the ordered pairs would go as follows according to the arrows:

(1, A), (2, A), (2, B), (3, C)

While the y-values, A and B, are different, they share the same input, 2. Therefore, the relation represented by the 4th diagram is NOT a function.

Hope this helps!

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.