kak tolong bantu jawab yh pake cara

Klo salah sorry ya
Jadiin jawaban terbaik ya :))
43. (2x-1) + (x+3) + (3x-1) = 19
2x-1+x+3+3x-1=19
2x+x+3x-1+3-1=19
6x-1=19
6x=19-1
6x=18
x= 18 : 6
x= 3

43
a=(2x-1) cm
b=(x+3) cm
c=(3x-1) cm
K=19 cm

K=2x-1+x+3+3x-1
19=2x-1+x+3+3x-1
19+1+1-3=2x+x+3x
18=6x
x=3 cm

44
sudut total segitiga=180°
∠a=65°
∠b=40°
∠c=?

180°=∠a+∠b+∠c
180°=65°+40°+∠c
180°-65°-40°=∠c
∠c=75°