If 12 is added to twice of a number, then the result is 38 less than seven…
2024
If 12 is added to twice of a number, then the result is 38 less than seven times of that number. Find the square of this number.
- A.
289/4
- B.
169/4
- C.
81
- D.
100
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Correct answer: D
Let the number be x.
Form the equation from the problem statement: 12 added to twice the number equals 38 less than seven times the number.
This gives: 12 + 2x = 7x - 38
Bring x-terms to one side and constants to the other: 12 + 2x = 7x - 38 ⇒ 12 + 38 = 7x - 2x
So, 50 = 5x ⇒ x = 10
Square of the number: x^2 = 10^2 = 100
Answer: 100