help

Just cross multiply

 

3*12=36

8*5=4

                 36/4

                 simplified to 9

                 3/8*12/5=36/4=9

Don't CROSS multiply....just multiply the numerators and multiply the denominators

 

3/8  x 12/5 =    (3x12)/(8x5)   =  36/40 = 18/20  =  9/10