x•90=36810
x=36810÷90
x=409
409•90=36810
36810=36810
x÷90=990
x=90•990
x=89100
89100÷90=990
990=990
18360÷x=90
x=18360÷90
x=204
18360÷204=90
90=90
x•90=36810
x=36810÷90
x=409
409•90=36810
36810=36810
x÷90=990
x=90•990
x=89100
89100÷90=990
990=990
18360÷x=90
x=18360÷90
x=204
18360÷204=90
90=90