9.besar sudut ABD adalah... 10. Nilai x adalah... 11. Nilai x adalah...

9)
< ABD + < DBC = 90
x + 15 + 2x - 45 = 90
3x - 30 = 90
3x = 90 + 30
3x = 120
x = 120/3
x = 40°

< ABD = x + 15
< ABD = 40 + 15
< ABD = 55° (D)

10)
3x + 16 + 2x - 26 = 180
5x - 10 = 180
5x = 180 + 10
5x = 190
x = 190/5
x = 38° (B)

11)
x + 36 = 3x + 4
x - 3x = 4 - 36
- 2x = - 32
x = - 32/- 2
x = 16 (D)

9.) (x+15)+(2x-45)=90 derajat
x+2x+15-45 = 90 derajat
3x-30 = 90 derajat
3x = (90+30)derajat
3x = 120 derajat
x = 40 derajat

sudut ABD = (x + 15)derajat = 40 + 15 = 55 derajat

10.) (2x-25)+(3x+16) = 180 derajat
2x+3x-26+16 = 180 derajat
5x-10 = 180 derajat
5x = (180+10)derajat
x = 190/5
x = 38 derajat

11.) (x+36) = (3x+4)
x -3x = 4-36
-2x = -32
x = 16

semoga membantu dan bermanfaat