7. Which of the following relations represent
functions?

it’s the 1 question

Step-by-step explanation:

Functions have a single output for each input

A No  example: C maps to 16 or 17

B Yes

C Yes

D Yes

E No   example: x = 4 maps to either y = +4 or 7 = -4

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180