Millions are after hundred thousands.
F=1
Add 22 to both sides, then divide both sides by 3
B. is the only one we know for sure. We know that when we put in -2 we get exactly one answer or output.
9u-9t=18
original no. is 10t+u
reversed no. is 10u+t
so is (10u+t)-(10t+u)=18
hence, the ans is 9u-9t=18