(48+a) -15; (a+123)-a; 81-(a+21); 31-(a+11); (6+a+75)-75;117-(33-x+b)

Question

(48+a) -15; (a+123)-a; 81-(a+21); 31-(a+11); (6+a+75)-75;117-(33-x+b)

Answer 1

1) (48+а)-15= 48+а-15= 33+а
2) (а+123)-а= а+123-а= 123
3)81-(а+21)=81-а-21=60-а
4) 31-(а+11)= 31-а-11=20-а
5)(6+а+75)-75=6+а+75-75=6+а
6)117-(33-х+b)=117-33+x-b=84+x-b