perbandingan panjang dan lebar suatu persegi panjang 5:3.jika kelilingnya 240 cm .Luas persegi panjang=....…………cm² a)3.375 b)4.320 c)6.750 d)13.500 (jawab pakai

P:l = 5:3
K = 240
Dit. L
K = 2(p+l)
240 = 2(5x+3x)
240= 10x + 6x
15 = x

Disubstitusikan
L = p x l
L = 5x x 3x
L = (5x15)x(3x15)
L = 75 x 45
L = 3375 cm2

Semoga membantu (:

Panjang : lebar = 5 : 3
Maka,
Panjang = (5/8) × a
Lebar = (3/8) × a

K = 2p + 2l
240 = (2 × 5/8 × a) + (2 × 3/8 × a)
240 = 2a
a = 120


Jadi,
Panjang = (5/8) × a = 5/8 × 120 = 75
Lebar = (3/8) × a = 3/8 × 120 = 45

L = p × l = 75 × 45 = 3375