15 целых 3/28-( 4 целых 11/28+у)=7-1 целая 9/28

Question

15 целых 3/28-( 4 целых 11/28+у)=7-1 целая 9/28

Answer 1

143/28-(123/28+у)=196/28-37/28
143/28-123/28-у=159/28
20/28-у=159/28
у=20/28-159/28
у=-139/28
у=-4 27/28