By solve do you mean balance? If you do then
2 Al + 6 NaOH = 2 Na₃AlO₃ + 3 H₂
because:
Al + NaOH = Na3AlO3 + H2
There must be the same number of atoms of each element both sides of the equation, therefore to balance the equation there must be more than 1 atom of elements otherwise there will be left over atoms
