diketahui segitiga samakaki PQR dngn panjang PR=Qr.jika panjang PQ=9x-5 ,QR=8x-8,PR =5x+4 berapa kaliling segitiga tersebut a.76 b.77 c.78 d.79

PR = QR
5x + 4 = 8x - 8
4 + 8 = 8x - 5x
12 = 3x
x = 12/3 = 4

Keliling = jmlh ketiga sisi
K = (9x -5) + (8x - 8) + (5x + 4)
K = (9x + 8x + 5x) - 5 - 8 + 4
K = 22x - 9
K = 22(4) - 9
K = 88 -9
K = 79 cm

D.

PR = QR
5x + 4 = 8x - 8
5x - 8x = -8 - 4
-3x = -12
x = 4

maka
PR = 5(4) + 4 = 24cm
QR = 8(4) - 8 = 24 cm
PQ = 9(4) - 5 = 31 cm

keliling segitiga
= 24 + 24 + 31
= 79 cm