Combine Logarithmic Expressions: Combine the logarithmic expressions using the product rule for logarithms, which states that log(a)+log(b)=log(ab).log10(3x+1)+log10(2x−5)=0log10((3x+1)(2x−5))=0
Convert to Exponential Form: Convert the logarithmic equation to its exponential form. Since log10(y)=x is equivalent to 10x=y, we can write:100=(3x+1)(2x−5)
Simplify Exponential Expression: Simplify the exponential expression, knowing that 100=1. 1=(3x+1)(2x−5)
Expand Equation: Expand the right side of the equation.1=6x2−15x+2x−51=6x2−13x−5
Set Quadratic Equation to Zero: Move all terms to one side to set the quadratic equation to zero.0=6x2−13x−5−10=6x2−13x−6
Factor or Use Quadratic Formula: Factor the quadratic equation, if possible, or use the quadratic formula to find the values of x. The quadratic formula is x=2a−b±b2−4ac. In this case, a=6, b=−13, and c=−6. Discriminant: Δ=b2−4ac=(−13)2−4(6)(−6)=169+144=313 Since the discriminant is positive, there are two real solutions.
Calculate Solutions: Calculate the solutions using the quadratic formula.x=2⋅6−(−13)±313x=1213±313
Check Validity of Solutions: Check for extraneous solutions by plugging the values of x back into the original logarithmic expressions to ensure that the arguments of the logarithms are positive.For x=1213+313:3x+1=3(1213+313)+1>02x−5=2(1213+313)−5>0Both expressions are positive, so this is a valid solution.
Check Second Solution: Check the second solution for x=1213−313:3x+1=3(1213−313)+12x−5=2(1213−313)−5We need to check if these expressions are positive.
Check Second Solution: Check the second solution for x=1213−313: 3x+1=3(1213−313)+1 2x−5=2(1213−313)−5 We need to check if these expressions are positive.Calculate the expressions to ensure they are positive. 3x+1=3(1213−313)+1 This expression is positive because 313 is less than 13, so (13−313) is positive, and multiplying by 3 and adding 1 keeps it positive. 2x−5=2(1213−313)−5 This expression is negative because 313 is greater than 3x+1=3(1213−313)+11, so (13−313) is negative, and multiplying by 3x+1=3(1213−313)+13 and subtracting 3x+1=3(1213−313)+14 keeps it negative. Since 3x+1=3(1213−313)+15 is negative, this solution is not valid for the logarithmic equation.
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