Tolong dong................

1. KΔABC = 120
AB + BC + AC = 120
40 + x + y = 120
x + y = 80

BC - AC = 20
x - y = 20

jadi jawaban C

2.
2x - y = 13
4y + 3x = 36 atau 3x + 4y = 36
jadi jawaban C