Question

Diketahui panjang persegi panjang 2 kali lebarnya. jika keliling persegi panjang tersebut 42 cm, maka luasnya adalah...?

Answer 1

P = 2x
l = x
2(2x + x) = 42
4x + 2x = 42
6x = 42
x = 42: 6
x = 7

p= 2x = 2 X 7 = 14 cm
l = x = 7 cm
luas = p X l = 14 X 7 = 98 cm2

Answer 2

X = 2y
2x + 2y = 42

2( 2y ) + 2y = 42
4y + 2y = 42
6y = 42
y = 7

x = 2( 7 )
x = 14

Panjang = 14 cm
Lebar = 7 cm

L = P . L
L = 14 . 7
L = 98 cm²