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4 votes
Identify a solution of the equation: log2x+log(x−5)=2

1. x= -4
2.x= 2
3.x= 10
4.x= 5

User Siri
by
6.4k points

1 Answer

4 votes

Answer:

  • 3.x= 10

Explanation:

  • log 2x + log (x - 5) = 2
  • log (2x(x - 5)) = 2
  • 2x(x - 5) = 10²
  • 2(x² - 5x) = 100
  • x² - 5x - 50 = 0
  • x² + 5x - 10x - 50 = 0
  • x(x + 5) - 10(x + 5) = 0
  • (x - 10)(x + 5) = 0
  • x = 10
  • x = -5, this root is discounted as log should be positive.

Correct choice is 3.

User Abdalrahman
by
6.3k points
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