sebuah segiempat mempunyai panjang (4x + 3) dan lebarnya (6x-4). c. jika x =3 tentukanlah keliling dan luasnya

Mapel : Matematika
Bab : Bangun Datar

Keliling persegi panjang
= 2 x ( p + l )
= 2 x ( 4x + 3 + 6x - 4 )
= 2 x ( 10x - 1 )
= 2 x ( 10.3 - 1 )
= 2 x ( 30 - 1 )
= 2 x 29 cm
= 58 cm

Luas persegi panjang
= p x l
= (4x + 3)(6x - 4)
= (4.3 + 3)(6.3 - 4)
= (12+3)(18-4)
= 15 cm x 14 cm
= 210 cm²

Diket: p= (4x + 3) l= (6x - 4) x=3
Dit: K...? L...?

Jawab:
p= (4x + 3) = 4.3 + 3 = 12 + 3 = 15
l = (6x - 4) = 6.3 - 4 = 18 - 4 = 14

K= 2 (p+l)
= 2 (15+14) = 2 (29) = 58 cm

L = p×l
= 15 × 14
= 210 cm2

Semoga bermanfaat.