Question

1. Grace was given the equation 2x + 20 = 15. She decides to add 10 to both sides of the equation. a.) Is that an acceptable move? b.) What would her new equation be?​

Answer 1

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Answer:

• yes
• 2x +30 = 25

Explanation:

Adding the same number to both sides of the equation is an acceptable move. The addition property of equality tells Grace that the value of the variable will remain unchanged by such a move.

Her new equation would be ...

2x +20 +10 = 15 +10

2x +30 = 25 . . . . the result of Grace's move

_____

Additional comment

There may be very good reasons why Grace would want to do that. If solving the equation is Grace's intent, that move would be counterproductive. For the purpose of solving the equation, it would be more productive to either subtract 20 from both sides, or divide both sides by 2. These steps would give, respectively, ...

2x = -5

x +10 = 7.5