Multiply 5t2*2t5

Do you mean this:

$${\mathtt{5}}{\mathtt{\,\times\,}}{{\mathtt{t}}}^{{\mathtt{2}}}{\mathtt{\,\times\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{{\mathtt{t}}}^{{\mathtt{5}}} = {\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{5}}{\mathtt{\,\times\,}}{{\mathtt{t}}}^{{\mathtt{2}}}{\mathtt{\,\times\,}}{{\mathtt{t}}}^{{\mathtt{5}}} = {\mathtt{10}}{\mathtt{\,\times\,}}{{\mathtt{t}}}^{{\mathtt{7}}}$$

Gruß radix !