What is the solution to the rational equation..
\[\frac{ x }{ x^2-9 }+\frac{ 1 }{ x-3 }=\frac{ 1 }{ 4x-12 }\]
Hint: first step, factorize the first denominator: \(\frac{ x }{ (x+3)(x-3) }+\frac{ 1 }{ x-3 }=\frac{ 1 }{ 4x-12 }\) and add the left-hand side to make one fraction to get: \(\dfrac{ x + (x+3) }{ (x+3)(x-3) }=\dfrac{ 1 }{ 4x-12 }\) \(\dfrac{ 2x+3 }{ (x+3)(x-3) }=\dfrac{ 1 }{ 4x-12 }\) Now cross multiply and solve the resulting quadratic. However, watch the denominators. All solutions giving x=3 or x=-3 must be rejected
In order to avoid a quadratic, multiply every term by 4x - 12 or 4(x-3) you should get the equation 4 + (4x)/(x + 3) = 1
Combine the left side using the common denominator (x+3). Solve the linear equation by clearing the fraction by multiplying both sides by (x + 3).
After that is done here is what you have 4(2x+3)=x+3. Simplify and solve for x
Very true, we can take advantage of the fact that 4x-12 = 4(x-3) which is already a factor, so no need to make it into a quadratic. \(\rm\frac{ x }{ x^2-9 }+\frac{ 1 }{ x-3 }=\frac{ 1 }{ 4x-12 }\) \(\rm\frac{ 4x }{ 4(x^2-9) }+\frac{ 4(x+3) }{ 4(x^2-9) }=\frac{ x+3 }{ 4(x^2-9) }\) Extract the numerators and solvefor x: \(\rm 4x+(4x+12) = x+3\)
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