Tolong yg ini dijawab dengan cara nomor 5 & 6 thank's

5. x+50 + x-30 = 180
2x = 180-50+30
x = 160/2 = 80

6. 54+3x = 180
3x = 180-54
x = 126/3 = 42

4y = 3x
4y = (3*42)
y = 126/4 = 31,5

x+y = 42+31,5 = 73,5