Answer and Step-by-step explanation:
The computation is shown below:
As we assume a and b are together and c and d are together
So, the equation would be
![= ab * cd](https://img.qammunity.org/2021/formulas/mathematics/high-school/3ujksvrpcdloq1z3cl8loxrzd2exx57ku1.png)
![= (10a + b) * (10c + d)](https://img.qammunity.org/2021/formulas/mathematics/high-school/kgr8zr0wfl01w4tf1bfit6pko8ud2vvf62.png)
= 100ac + 10(ad + bc) + bd
Now another equation i s
![= ba * cd](https://img.qammunity.org/2021/formulas/mathematics/high-school/3ful7vreg3q8jymyhazk68wpwi0dnm6o7g.png)
![= (10b + a) * (10d + c)](https://img.qammunity.org/2021/formulas/mathematics/high-school/60nns3mm27tsfizki8p6kov8jlvs2ddm34.png)
= 100bd + 10(ad + bc) + ac
Now take both equations together
So,
100ac + 10(ad + bc) + bd = 100bd + 10(ad + bc) + ac
99ac = 99bd
ac = bd
Now Like here a = 2 b = 10 and c = 5 d = 1
So,
ac = bd = 10
So we can take an example like this
So, by considering the
![62 * 13 = 806](https://img.qammunity.org/2021/formulas/mathematics/high-school/rsqmg17m88dfx8wb6u6iw3cscvpptqwrd4.png)
And,
![26 * 31 = 806](https://img.qammunity.org/2021/formulas/mathematics/high-school/v03n01a9xu7huhsx8nioy41gmsl10buji7.png)
We can the same amount
So in the given question, the choices are not there so we can calculate by the above method