it is 89 ok
x8+9=81 -9 -9 x8 =72 /8 /8 x= 9
It is: 11+5+32+81 = 129
78 + 79 + 80 + 80 + 81 + 81 = 479
9n+9=81 9n=72 n=8
It is 8(80b+81) when factored
8 + 2/12 = 49/6 or 81/6
81*82/2= 3321
1/4 plus3/8 = 5/81/4 + 3/8= 2/8 + 3/8= 5/8
-81
81
105 + 66 + 287 + 81 = 539
65/8 = 1625/200 7/25 = 56/200 1681/200 = 8 and 81/200