А)5/33-(7/11-1/3) = 5/33- 7/11+1/3и 5/33+(1/3-7/11)=5/33+1/3-7/11. те выражения равныб)7/20:3/4+1/5= 7*4/20*3 + 1/5= 7/15+1/5=10/15=2/3
и 7/20:(3/4+1/5)=7/20/( (3*5+4)/20)=7/20 / 19/20=7/20 *20/19= 7/19
2/3=38/57, а 7/19=21/57, т.к 38/57>21/57. то 7/20:3/4+1/5 > 7/20:(3/4+1/5)