If the question mark means the same on each side of the equation then there is no solution because the equation is false. 8 x ? = ? x 8 in normal multiplication, because the order of the multiplicands doesn't matter. So we're left with 0=4x8 which isn't true. The brackets don't make any difference because the priority rules put multiplication before addition.
If the question marks mean something different on each side of the equation, then we have a relationship or linear equation for which there are an infinite number of solutions: 8y=8x+32, effectively. This simplifies to y=x+4. This can be represented by a straight line for which each point on the line is a solution.
A third alternative speculates that "x" does not mean multiply so that 8x? does not mean the same as ?x8. An example would be that x means divide, where the order of the operands matters. But then we're left to speculate what + means, opening the way to endless possibilities.