Question

Sebuah persegi panjang mempunyai ukuran 3x - 4cm dan lebar x + 1 cm. tentukan luas persegi panjang tersebut jika keliling nya 34cm

Answer 1

K = 2(p + l)
34 = 2(3x - 4 + x + 1)
17 = 4x - 3
4x = 20
x = 5 cm

p = 3(5) - 4 = 11 cm
l = 5 + 1 = 6 cm
L = p x l
L = 11 cm x 6 cm
L = 66 cm^2

Answer 2

34 = 2 (3x - 4 + x + 1)
34 = 2 (4x - 3)
34 = 8x - 6
34 + 6 = 8x
40 = 8x
x = 5

jadi luas persegipanjang
= ( 3x - 4 )( x + 1 )
= (15 - 4 ) ( 5 + 1)
= 11 x 6
= 66 cm2