kak tolong bantu yang nomer 7 sama 8 ya..

7. menentukan nilai a dan c
(a) 360° = 2a°+3a°+4a°
360° = 9a°
360°/9° = a
40 = a

(b) 360° = 56°+89°+4c+3c
360° = 145° + 7c
360°-145° = 7c
215° = 7c
215°/7° = c
30,71429 = c

8. menentukan nilai x dan y
(a) 360° = 90°+90°+3x°+6x°
360° = 180° + 9x°
360°-180° = 9x°
180° = 9x°
180°/9° = x
20 = x

(b) 360° = 90°+65°+2y+3y
360° = 155° + 5y
360° - 155° = 5y
205° = 5y
205°/5° = y
41 = y

semoga membantu ;)