Dik = p : (3x+2) l : (5x+3) k : 42 cm Dit = nilai x ?

Keliling Persegi Panjang = 2 × (p+l)
42 cm = 2 × (p+l)
42 cm = 2 × [(3x+2) + (5x+3)]
42 cm = 2 × (8x + 5)
42 cm = 16x + 10
16x = 42 - 10
16x = 32
x = 2 cm

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(Jgn lupa follow)