In least to greatest 3/8 - 1/2 1/4 - 3/4

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

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?