justification

annad95

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Nov 30, 2011
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The steps to solving an equation are shown below. Provide a justification for steps 2, 3, and 4.

1. 8x – 5 = -2x - 15. 1. Given
2. 10x – 5 = -15. 2.
3. 10x = -10. 3.
4. x = -1. 4.
 
2. 10x-5=-15 multiply of equality
3. 10x=-10 adding of equality
4. x=-1 divide of equality
 
The steps to solving an equation are shown below. Provide a justification for steps 2, 3, and 4.

1. 8x – 5 = -2x - 15. 1. Given
2. 10x – 5 = -15. 2.

2. 10x-5=-15 multiply of equality

Is that your final answer? (meaning: are you sure about that?)
 
Hello, annad95!

The steps to solving an equation are shown below.
Provide a justification for steps 2, 3, and 4.

\(\displaystyle \begin{array}{ccccccc}1.& 8x - 5 \:=\: -2x - 15 && 1.& \text{Given } \\
2. & 10x - 5 \:=\: -15 && 2. & --- \\
3. & 10x \:=\: -10 && 3. & --- \\
4. & x \:=\: -1 && 4. & --- \end{array}\)

Here's my version . . .


\(\displaystyle \begin{array}{ccccccccc}1.& 8x - 5 \:=\: -2x - 15 && 1.& \text{Given } \\
2. & 10x - 5 \:=\: -15 && 2. & \text{add'n of equality} & \text{(Add }2x\text{ to both sides)} \\
3. & 10x \:=\: -10 && 3. & \text{add'n of equality} & \text{(Add 5 to both sides)} \\
4. & x \:=\: -1 && 4. & \text{div'n of equality} & \text{(Divide both sides by 10)} \end{array}\)
 
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