tolong du jawab dengan benar please

A.
24x²y/7z³ × 21y²z²/9x
= 504x²y³z²/63xz³
= 504x²y³z² ÷ 63 xz²/63xz³ ÷ 63xz²
= 8xy³/z

B.
2m + 8/m² × 3m/2m² - 32
= 2(m + 4)/m × 3/2(m² - 16)
= 2(m + 4)/m × 3/2(m - 4)(m + 4)
= (m + 4)/m × 3/(m - 4)(m + 4)
= 1/m × 3/m - 4
= 3/m² - 4m

Maaf Kalau Salah