Tolong cara nya yg no.15. Trims

p = (2x + 5) cm
l = (x + 3) cm
K = 46 cm

K = 2(p + l)
46 = 2(2x + 5 + x + 3)
46 = 2(3x + 8)
3x + 8 = 46 / 2
3x + 8 = 23
3x = 23 - 8
3x = 15
x = 5

Panjang = 2x + 5
              = 2(5) + 5
              = 10 + 5
              = 15 cm

Lebar = x + 3
          = 5 + 3
          = 8 cm

Jawaban B