3. Sebuah persegi panjang sisinya (6x + 2) cm. Keliling persegi = 112 cm. Tentukan: a. nilai x b. panjang sisi persegi C. luas persegi
S = ( 6x + 2 ) cm
K = 112 cm = 4 × S
a. Nilai x
112 = 4 ( 6x + 2 )
112 = 24x + 8
112 - 8 = 24x
104 = 24x
x = 104/24
[tex]x = 4 \frac{1}{3} = \frac{13}{3} [/tex]
b. panjang sisi persegi
S = ( 6x + 2 )
[tex] \sf{S = 6( \frac{13}{3} ) + 2}[/tex]
S = 2 × 13 + 2
S = 26 + 2
S = 28 cm
C. Luas persegi
L = S × S
L = 28 cm × 28 cm
L = 784 cm²
[answer.2.content]
