tolong no 1 ya pakai cara

panjang = 3x - 12 = 2x + 4
3x - 2x = 4 + 12
x = 16 cm
sisi panjang = 3( 16) - 12 = 36 cm
sisi panjang = 2(16) + 4 = 36 cm
lebar = 4x = 2x +6
4x- 2x = 6
2x = 6
x = 3 cm
sisi lebar = 4( 3) = 12 cm
sisi lebar = 2( 3) +6 = 12 cm
jadi luas persegi panjang = p × l
= 36 × 12 = 432 cm^
Keliling persegi panjang = 2 ( p+ l )
= 2( 36 + 12 )
= 96 cm