раскройте скобки и упростите выражение (x-5,25)+4 1/4-x) (7 1/3-y)-(2 2/9-y) a+b+(-c+d)

Решите задачу:

$1.)\ (x-5,25)+(4\frac{1}{4}-x)=x-5,25+4\frac{1}{4}-x=4\frac{1}{4}-5,25=\\\\ =\frac{17}{4}-\frac{525}{100}=\frac{425}{100}-\frac{525}{100}=-\frac{100}{100}=-1\\\\ 2.)\ (7\frac{1}{3}-y)-(2\frac{2}{9}-y)=7\frac{1}{3}-y-2\frac{2}{9}+y=7\frac{1}{3}-2\frac{2}{9}=\\\\ =\frac{22}{3}-\frac{20}{9}=\frac{66}{9}-\frac{20}{9}=\frac{46}{9}=5\frac{1}{9}\\\\ 3.)\ a+b+(-c+d)=a+b+(d-c)=a+b+d-c$