раскройте скобки и упростите выражение 4y-(3y-(2y-(y+1)))

f(y)=4y-(3y-(2y-(y+1)))

f(y)=4y-(3y-(2y-y-1))

f(y)=4y-(3y-(y-1))

f(y)=4y-(3y-y+1))

f(y)=4y-3y+y-1

f(y)=2y-1