Answer: " x = 9 " .
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Explanation:
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To calculate the mean:
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The mean =
{the sum of all the values in the number set} ÷
{the number of values in the data set} ;
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To solve for "x" ;
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Given that the "mean" is: "8" ;
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8 = { 3 + 7 + 9 + 12 + x } / 5 ;
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↔ { 3 + 7 + 9 + 12 + x } / 5 = 8 ;
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→ { 3 + 7 + 9 + 12 + x } = 8 * 5 ;
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→ { 31 + x } = 40 ;
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↔ x + 31 = 40 ;
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Subtract "31" from EACH SIDE of the equation; to isolate "x" on one side of the equation; and to solve for "x" ;
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→ x + 31 − 31 = 40 − 31 ;
→ x = 9 .
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Consider this solution.
If it is possible, check it in the other sources.
Answer:
66 I think might he wrong
Step-by-step explanation:
I'm not sure if its right
Solutions
In Matrix we use initially based on systems of linear equations.The matrix method is similar to the method of Elimination as but is a lot cleaner than the elimination method.Solving systems of equations by Matrix Method involves expressing the system of equations in form of a matrix and then reducing that matrix into what is known as Row Echelon Form.<span>
Calculations
</span>⇒ <span>Rewrite the linear equations above as a matrix
</span>
⇒ Apply to Row₂ : Row₂ - 2 <span>Row₁
</span>
⇒ <span>Simplify rows
</span>
Note: The matrix is now in echelon form.
<span>The steps below are for back substitution.
</span>
⇒ Apply to Row₁<span> : Row</span>₁<span> - </span>5 Row₂
⇒ <span>Simplify rows
</span>
⇒ <span>Therefore,
</span>

<span>
</span>
Answer:
102
Step-by-step explanation:
408 words / 4 min = 102 words per min