Question

Solve the subtraction problem 8/9 - 3/4

Answer 1

Find the common denominator first which would be 36. So you have ti multiple the denominator and numerator for 8/9 by 4 (top and bottom). The new fraction would be 32/36.
Now for 3/4 you have to multiple numerator and denominator by 9. So the new fraction would be 27/36.
Now subtract 32/36 - 27/36 = 5/36 
Which cannot be reduced so that's your answer. Hope the explanation is clear enough. 

Answer 2

$\dfrac{a}{b}-\dfrac{c}{d}=\dfrac{ad-bc}{bd}$


$\dfrac{8}{9}-\dfrac{3}{4}=\dfrac{8\cdot4-9\cdot3}{9\cdot4}=\dfrac{32-27}{36}=\boxed{\frac{5}{36}}$