78 ∙ х 3217, если х = 52
a : 36 + a : 39, если a = 46
х ∙ 37 - в : 25, если х = 15

78 ∙ 52 + 3217=7273;

46/36+46/39=46/(3*12)+46/(3*13)=(46*13+46*12)/3*12*13=1150/468=2 214/468=

=2 107/234;

15*37-b/25=555-b/25