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Resolve `(3x^(2)-3x-11)/((x+3)(3x+4)^(2))` into partial fractions.A. `(1)/(x+3)+(2)/(3x+4)-(1)/((3x+4)^(2))`B. `(1)/(x+3)-(2)/(3x+4)-(1)/((3x+4)^(2))`C. `(1)/(x+3)+(2)/(3x+4)-(1)/(2(3x+4)^(2))`D. None of these

Answer» Let, `(3x^(2)-3x-11)/((x+3)(3x+4)^(2))=(A)/(x+3)+(B)/(3x+4)+(C )/((3x+4)^(2))`
Consider
`3x^(2)-3x-11=A(3x+4)^(2)+B(x+3)(3x+4)+C(x+3)`
`=A(9x^(2)+16+24x)+B(3x^(2)+13x+12)+C(x+3)`
Comparing coefficient of `x^(2)`, coefficient of `x` and constant terms, we get,
`9A+3B=3`.......`(1)`
`24A+13B+C=-3`.........`(2)`
`16A+12B+3C=-11`.......`(3)`
Solving Eqs. `(1)`, `(2)` and `(3)`, we get
`A=1`, `B=-2`, `C=-1`
`:.(3x^(2)-3x-11)/((x+3)(3x+4)^(2))=-(1)/(x+3)-(2)/(3x+4)-(1)/((3x+4)^(2))`


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