Selisih panjang dan lebar sebuah persegi panjang adalah 6 cm.jika luasnya 112 cm² ,tentukan keliling persegi panjang tersebut...tolong dijawab..terima kasih
P = a l = a + 6 L = p x l 112 = a x (a+6) 112 = a2 + 6a a2 + 6a -112 = 0 (a-8) (a+14) = 0 a = 8 atau a = -14 maka p = 8 l = 8 + 6 = 14 K = 2 (p+l) = 2(6+14) = 2 x 20 = 40 cm
Verified answer
P = al = a + 6
L = p x l
112 = a x (a+6)
112 = a2 + 6a
a2 + 6a -112 = 0
(a-8) (a+14) = 0
a = 8 atau a = -14
maka
p = 8
l = 8 + 6 = 14
K = 2 (p+l)
= 2(6+14)
= 2 x 20
= 40 cm