Question

What is the justification for the step taken from line 2 to line 3?

Answer 1

Step-by-step explanation:

$3x+9-7x=x+10+x\\-4x+9=2x+10\\-6x+9=10$

• In the line 2, only variables were operated with a reduction of similar terms in each side of the equation, giving as result -4x at one side, and 2x at the other side.
• In the line 3, terms with variables were joined together in one side of the equation, and then, they were operate it, given as result -6X.

Answer 2

Answer:

the subtraction property of equality

Step-by-step explanation:

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