Tolong di jawab yah kak

[tex]21. \frac{ac}{15} = \frac{8}{10} \\ 10ac = 15 \times 8 \\ ac = \frac{120}{10} \\ ac= 12 \\ \\ 29. \: \frac{8}{6} = \frac{pq}{3} \\ 6pq = 8 \times 3 \\ pq = \frac{24}{6} \\ pq = 4 \\ [/tex]