Answer:
sum_of_interior_angles = (number_of_sides - 2) x 180° → if number_of_sides is 21: sum = (21 - 2) x 180° = 19 x 180° = 3420°
Step-by-step explanation:
21x10 is 210 your welcome
Hey use the symbolab it can work with these type of equations xoxo
Answer and work down below
6x + 3 = -4y + 11
- 3 - 3
6x = -4y + 8
6x + 4y = -4y + 4y + 8
6x + 4y = 8
6x - 6x + 4y = -6x + 8
4y = -6x + 8
4 4
y = -1¹/₂x + 2