yang bisa, jawab pakai cara ya

s = 1/2-√2

Luas permukaan kubus = 6 × s²
Luas permukaan kubus = 6 × (1/2-√2)²
= 6 × 1/(2-√2)²
= 6 × 1/4-4√2+2
= 6 × 1/6-4√2
= 6 × 1/2(3-2√2)
= 3 × 1/3-2√2
= 3/3-2√2
= 3(3+2√2)
= 9+6√2
ket: / = -/per