Kunci Jawaban Matematika Kelas 9 Halaman 266 Nomor 15 Menghitung Panjang Sisi Segitiga

EC = 2/6 x 9 = 3 cm

AE = AC – EC = 9 – 3 = 6 cm

d. CF/CB = EF/AB

CF/CF+4 = 5/7

7 x CF = 5 (CF + 4)

7 CF = 5 CF + 20

2 CF = 20

CF = 20/2 = 10 cm

7 CF – 5 CF = 20