No 21. Itu 5y , 7x+16 Bantu jawab sama carany y :((

2x + 25° : 115°
2x : 115° - 25°
2x : 90°
X : 45°

no 20.
7x + 16 = 135
7x = 119
x = 17

** 5y + 135 = 180
5y = 45
y = 9

x + y = 17 + 9
= 26