8 per 9 dikali 5 per 7 dikurang 1 per 2

[tex] \frac{8}{9} \times \frac{5}{7} - \frac{1}{2} \\ \\ = \frac{40}{63} - \frac{1}{2} \\ \\ = \frac{80}{126} - \frac{63}{126} \\ \\ = \frac{17}{126} [/tex]

8/9 ×5/7 - 1/2
= 40 /63 - 1/2 (dahulukan prkalian/ pmbagian
= 80/126 - 63/126
= 17/126