(2/9)-(7/16)*(2/9)=(2/9)*(1-7/16)=(2/9)*(9/16)=1/8
2/9-7/16×2/9=2/9×(1-7/16)=2/9×9/16=1/8
2/9-7/16*2/9=2/9*(1-7/16)=2/9*9/16=1/8