ini yg paling sulit master kepalaku pening no 18 n 19

3x - 42 = 2x + 7
3x - 2x = 7 + 42
         x = 49

      3x - 42 + y + 42 = 180
3 (49) - 42 + y + 42 = 180
   147 - 42 + y + 42 = 180
y = 180 - 147
y = 33

x + y
= 49 + 33
= 82


A+B = 90° -> saling berpelurus
perbandingan -> A : B = 2 : 3
jumlah perbandingan ->  2+3 = 5

<A = 2/5 × 90° = 36°

Pelurus Sudut A
= 180°- 36°
= 144°


Semoga Membantu!!!

3x-42 = 2x+7
3x-2x=7+42
x=49

2x+7+y+42=180
2x+y=180-7-42
2x+y=131
2(49)+y=131
98+y=131
y=131-98
y=33

x+y=49+33=82