Find the value of X.

19) 28°

20) 60°

21) 17°

Step-by-step explanation:

19)

Supplementary angles:

(x + 12)º + 140º = 180º

x + 12 + 140 = 180

x = 180 - 140 - 12

x = 28º

20)

Angles at a point:

(- 24 + x)° + 24° + 300° = 360°

- 24 + x + 24 + 300 = 360

x = 360 - 300

x = 60°

21)

Vertically opposite angles:

(1 + 3x)° = 52°

1 + 3x = 52

3x = 52 - 1

3x = 51

x = 17°

80% of the cookies

step-by-step explanation: