Is c correct? and what goes in the box?

Which addition property is being illustrated below? (type commutative or associative) (6 + 7) + 1 = 6 + (7 + 1)

Use the expression below.–4b + 8c + 12 – 8b – 2c + 6part asimplify the expression. enter your answers in the boxes. b + c + part bfactor the simplified expression using the gcf. a. 2(–2b + c + 3) b. 3(–2b + c + 3) c. 4(–2b + c + 3) d. 6(–2b + c + 3)part cwhat is the value of the expression when b = 2 and c = –3? enter your answer in the box.

Plz hurry evaluate the expression a+b where a=8 and b=19