sebuah persegi panjang ( 2x-1 ) lebar ( x+3 ) keliling 64. maka luasnya

k = 2(p + l )
64= 2 (2x-1 + x + 3)
64 = 2 ( 3x + 2)
64 = 6x +4
64-4 = 6x
60 = 6x
x = 60/6
x = 10
p = 2.10-1 = 19
l = 10 + 3 = 13

luas = pxl
= 19 x 13
= 247