Question

Identify the algebraic property of equality. If 2x + y = 9 and y = 3, then 2x +3 = 9.

Answer 1

The substitution property of equality states that if x = y, then x can be substituted in for y in any equation, and y can be substituted for x in any equation.

In the case of the question, y = 3 is substituted in 2x + y = 9 to get 2x + 3 = 9