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x-2-log-5-x-x-5x-4-log-x-5-x-




Question Number 83786 by jagoll last updated on 06/Mar/20
(x^2 /(log_((5−x))  (x))) ≤ (5x−4) log_x  (5−x)
x2log(5x)(x)(5x4)logx(5x)
Answered by john santu last updated on 06/Mar/20
x^2  log_x  (5−x) ≤ (5x−4) log_x  (5−x)  (x−1)((5−x)^x^2  −(5−x)^(5x−4) ) ≤ 0  (i) x > 0 ∧ x ≠ 1 ∧x ≠ 4 ∧ x < 5  ⇒ for x < 1 ⇒ x^2 −5x+4 ≥ 0   (x−1)(x−4) ≥0 , ⇒ x < 1  ⇒ for x > 1 ⇒ x^2 −5x+4 ≤ 0  1 < x < 4  the solution is 0 < x < 1∨ 1 < x < 4
x2logx(5x)(5x4)logx(5x)(x1)((5x)x2(5x)5x4)0(i)x>0x1x4x<5forx<1x25x+40(x1)(x4)0,x<1forx>1x25x+401<x<4thesolutionis0<x<11<x<4
Commented by jagoll last updated on 06/Mar/20
thank you sir , but the   answer is 0 < x < 1 ∨ 1 < x < 4   ∨ 4 < x < 5
thankyousir,buttheansweris0<x<11<x<44<x<5
Answered by MJS last updated on 07/Mar/20
x^2 ((ln (5−x))/(ln x))≤(5x−4)((ln (5−x))/(ln x))  0<x<5 ∧ x≠1 ∧ x≠4  case 1 ((ln (5−x))/(ln x))>0 ∧ x^2 ≤5x−4       case 1.1 ln (5−x) <0 ∧ ln x <0            no solution       case 1.2 ln (5−x) >0 ∧ ln x >0            1<x<4       x^2 −5x+4≤0 ⇒ 1≤x≤5  ⇒ 1<x<4  case 2 ((ln (5−x))/(ln x))<0 ∧ x^2 ≥5x−4       case 2.1 ln (5−x) <0 ∧ ln x >0            4<x<5       case 2.2 ln (5−x) >0 ∧ ln x <0            0<x<1       x^2 −5x+4≥0 ⇒ x≤1 ∨ x≥4  ⇒ 0<x<1 ∨ 4<x<5    answer x∈]0; 5[\{1; 4}  but regarding the limits we could define for  0≤x≤5
x2ln(5x)lnx(5x4)ln(5x)lnx0<x<5x1x4case1ln(5x)lnx>0x25x4case1.1ln(5x)<0lnx<0nosolutioncase1.2ln(5x)>0lnx>01<x<4x25x+401x51<x<4case2ln(5x)lnx<0x25x4case2.1ln(5x)<0lnx>04<x<5case2.2ln(5x)>0lnx<00<x<1x25x+40x1x40<x<14<x<5answerx]0;5[{1;4}butregardingthelimitswecoulddefinefor0x5

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