Let w be the age of William now
Let r be the age of Robert now
(w-2) + (r-2) = 53 - ⓵
(10 + w) = 5/6(10 + r) - ⓶
From ⓶, w = 5/6(10 + r) - 10
           = 25/3 + 5/6r - 10
           = (-5/3) + 5/6r - ⓷
Put ⓷ into ⓵
    {[(-5/3) + 5/6r]-2} + (r-2) = 53
        -5/3 + 5/6r - 2 + r - 2 = 53
                       5/6r + r = 53 + 5/3 + 2 + 2
                          11/6r = 176/3
                            11r = 352
                              r = 32
Therefore William is 32 years old now.