tlong bntu y.... no.1 dan 2 pkai caranya ya....!

1. metode spldv
3a+20+2a=180
5a=180-20
5a=160
a=160/5
a=32

ditanya nilai<abd
3a+20
3(32)+20
96+20
<abd=116

2.menggunakan metos spldv
3x+4x+5=180
7x=180-5
x=175/7
x=25

dit besar <bac
<bac=180-75-50
<bac=55

1). <ABD + <CBD = 180⁰ (sudut pelurus)
(3a + 20)⁰ + 2a⁰ = 180⁰
5a + 20 = 180
5a = 180-20
5a = 160
a = 160/5
a = 32⁰
jadi besa <ABD = (3a + 20) = 3(32) + 20 = 96 + 20 = 116⁰

2). 3x + (4x + 5) = 180
7x + 5 = 180
7x = 180 - 5
7x = 175
x = 175/7
x = 25

=> <BAC + 3x + 50⁰ = 180⁰ (besar sudut segitiga)
=> <BAC + 3(25) + 50 = 180
=> <BAC + 75 + 50 = 180
=> <BAC + 125 = 180
=> <BAC = 180 - 125
=> <BAC = 55⁰