Mister Exam

Other calculators

Least common denominator ((x+5)/(x^2-81)+(x+7)/(x^2-18*x+81))/((x+3)^2)/((x-9)^2)+(7+x)/(9+x)

An expression to simplify:

The solution

You have entered [src]
/ x + 5        x + 7     \        
|------- + --------------|        
| 2         2            |        
|x  - 81   x  - 18*x + 81|        
|------------------------|        
|               2        |        
\        (x + 3)         /   7 + x
-------------------------- + -----
                2            9 + x
         (x - 9)                  
$$\frac{\left(\frac{x + 5}{x^{2} - 81} + \frac{x + 7}{\left(x^{2} - 18 x\right) + 81}\right) \frac{1}{\left(x + 3\right)^{2}}}{\left(x - 9\right)^{2}} + \frac{x + 7}{x + 9}$$
(((x + 5)/(x^2 - 81) + (x + 7)/(x^2 - 18*x + 81))/(x + 3)^2)/(x - 9)^2 + (7 + x)/(9 + x)
General simplification [src]
          5                 4        3        2
 45929 + x  - 13851*x - 29*x  + 234*x  + 486*x 
-----------------------------------------------
         5                 4        3         2
59049 + x  - 19683*x - 27*x  + 162*x  + 1458*x 
$$\frac{x^{5} - 29 x^{4} + 234 x^{3} + 486 x^{2} - 13851 x + 45929}{x^{5} - 27 x^{4} + 162 x^{3} + 1458 x^{2} - 19683 x + 59049}$$
(45929 + x^5 - 13851*x - 29*x^4 + 234*x^3 + 486*x^2)/(59049 + x^5 - 19683*x - 27*x^4 + 162*x^3 + 1458*x^2)
Fraction decomposition [src]
1 - 104975/(52488*(9 + x)) - 1/(162*(-9 + x)^3) - 1/(52488*(-9 + x)) + 1/(9*(-9 + x)^4) + 1/(2916*(-9 + x)^2)
$$1 - \frac{104975}{52488 \left(x + 9\right)} - \frac{1}{52488 \left(x - 9\right)} + \frac{1}{2916 \left(x - 9\right)^{2}} - \frac{1}{162 \left(x - 9\right)^{3}} + \frac{1}{9 \left(x - 9\right)^{4}}$$
        104975            1               1               1              1       
1 - ------------- - ------------- - -------------- + ----------- + --------------
    52488*(9 + x)               3   52488*(-9 + x)             4                2
                    162*(-9 + x)                     9*(-9 + x)    2916*(-9 + x) 
Rational denominator [src]
        //       2\                   /      2       \\           2        2 /       2\         /      2       \
(9 + x)*\\-81 + x /*(7 + x) + (5 + x)*\81 + x  - 18*x// + (-9 + x) *(3 + x) *\-81 + x /*(7 + x)*\81 + x  - 18*x/
----------------------------------------------------------------------------------------------------------------
                             /       2\         2        2         /      2       \                             
                             \-81 + x /*(-9 + x) *(3 + x) *(9 + x)*\81 + x  - 18*x/                             
$$\frac{\left(x - 9\right)^{2} \left(x + 3\right)^{2} \left(x + 7\right) \left(x^{2} - 81\right) \left(x^{2} - 18 x + 81\right) + \left(x + 9\right) \left(\left(x + 5\right) \left(x^{2} - 18 x + 81\right) + \left(x + 7\right) \left(x^{2} - 81\right)\right)}{\left(x - 9\right)^{2} \left(x + 3\right)^{2} \left(x + 9\right) \left(x^{2} - 81\right) \left(x^{2} - 18 x + 81\right)}$$
((9 + x)*((-81 + x^2)*(7 + x) + (5 + x)*(81 + x^2 - 18*x)) + (-9 + x)^2*(3 + x)^2*(-81 + x^2)*(7 + x)*(81 + x^2 - 18*x))/((-81 + x^2)*(-9 + x)^2*(3 + x)^2*(9 + x)*(81 + x^2 - 18*x))
Powers [src]
         5 + x         7 + x     
        -------- + --------------
               2         2       
7 + x   -81 + x    81 + x  - 18*x
----- + -------------------------
9 + x               2        2   
            (-9 + x) *(3 + x)    
$$\frac{x + 7}{x + 9} + \frac{\frac{x + 5}{x^{2} - 81} + \frac{x + 7}{x^{2} - 18 x + 81}}{\left(x - 9\right)^{2} \left(x + 3\right)^{2}}$$
(7 + x)/(9 + x) + ((5 + x)/(-81 + x^2) + (7 + x)/(81 + x^2 - 18*x))/((-9 + x)^2*(3 + x)^2)
Common denominator [src]
                              3      4        2    
         13120 - 5832*x - 72*x  + 2*x  + 972*x     
1 - -----------------------------------------------
             5                 4        3         2
    59049 + x  - 19683*x - 27*x  + 162*x  + 1458*x 
$$- \frac{2 x^{4} - 72 x^{3} + 972 x^{2} - 5832 x + 13120}{x^{5} - 27 x^{4} + 162 x^{3} + 1458 x^{2} - 19683 x + 59049} + 1$$
1 - (13120 - 5832*x - 72*x^3 + 2*x^4 + 972*x^2)/(59049 + x^5 - 19683*x - 27*x^4 + 162*x^3 + 1458*x^2)
Assemble expression [src]
         5 + x         7 + x     
        -------- + --------------
               2         2       
7 + x   -81 + x    81 + x  - 18*x
----- + -------------------------
9 + x               2        2   
            (-9 + x) *(3 + x)    
$$\frac{x + 7}{x + 9} + \frac{\frac{x + 5}{x^{2} - 81} + \frac{x + 7}{x^{2} - 18 x + 81}}{\left(x - 9\right)^{2} \left(x + 3\right)^{2}}$$
(7 + x)/(9 + x) + ((5 + x)/(-81 + x^2) + (7 + x)/(81 + x^2 - 18*x))/((-9 + x)^2*(3 + x)^2)
Numerical answer [src]
(7.0 + x)/(9.0 + x) + 0.00137174211248285*((5.0 + x)/(-81.0 + x^2) + (7.0 + x)/(81.0 + x^2 - 18.0*x))/((1 + 0.333333333333333*x)^2*(-1 + 0.111111111111111*x)^2)
(7.0 + x)/(9.0 + x) + 0.00137174211248285*((5.0 + x)/(-81.0 + x^2) + (7.0 + x)/(81.0 + x^2 - 18.0*x))/((1 + 0.333333333333333*x)^2*(-1 + 0.111111111111111*x)^2)
Trigonometric part [src]
         5 + x         7 + x     
        -------- + --------------
               2         2       
7 + x   -81 + x    81 + x  - 18*x
----- + -------------------------
9 + x               2        2   
            (-9 + x) *(3 + x)    
$$\frac{x + 7}{x + 9} + \frac{\frac{x + 5}{x^{2} - 81} + \frac{x + 7}{x^{2} - 18 x + 81}}{\left(x - 9\right)^{2} \left(x + 3\right)^{2}}$$
(7 + x)/(9 + x) + ((5 + x)/(-81 + x^2) + (7 + x)/(81 + x^2 - 18*x))/((-9 + x)^2*(3 + x)^2)
Combining rational expressions [src]
        //       2\                                     \           2        2 /       2\                           
(9 + x)*\\-81 + x /*(7 + x) + (5 + x)*(81 + x*(-18 + x))/ + (-9 + x) *(3 + x) *\-81 + x /*(7 + x)*(81 + x*(-18 + x))
--------------------------------------------------------------------------------------------------------------------
                              /       2\         2        2                                                         
                              \-81 + x /*(-9 + x) *(3 + x) *(9 + x)*(81 + x*(-18 + x))                              
$$\frac{\left(x - 9\right)^{2} \left(x + 3\right)^{2} \left(x + 7\right) \left(x^{2} - 81\right) \left(x \left(x - 18\right) + 81\right) + \left(x + 9\right) \left(\left(x + 5\right) \left(x \left(x - 18\right) + 81\right) + \left(x + 7\right) \left(x^{2} - 81\right)\right)}{\left(x - 9\right)^{2} \left(x + 3\right)^{2} \left(x + 9\right) \left(x^{2} - 81\right) \left(x \left(x - 18\right) + 81\right)}$$
((9 + x)*((-81 + x^2)*(7 + x) + (5 + x)*(81 + x*(-18 + x))) + (-9 + x)^2*(3 + x)^2*(-81 + x^2)*(7 + x)*(81 + x*(-18 + x)))/((-81 + x^2)*(-9 + x)^2*(3 + x)^2*(9 + x)*(81 + x*(-18 + x)))
Combinatorics [src]
         5                 4        3        2
45929 + x  - 13851*x - 29*x  + 234*x  + 486*x 
----------------------------------------------
                      4                       
              (-9 + x) *(9 + x)               
$$\frac{x^{5} - 29 x^{4} + 234 x^{3} + 486 x^{2} - 13851 x + 45929}{\left(x - 9\right)^{4} \left(x + 9\right)}$$
(45929 + x^5 - 13851*x - 29*x^4 + 234*x^3 + 486*x^2)/((-9 + x)^4*(9 + x))