Question:`A = x - 2, B = x^2 + 2x + 4, C = x^2 - 8` তিনটি বীজগাণিতিক রাশি।
ক. যোগফল নির্ণয় কর: `a/(bc) + b/(ca) + c/(ab) + (a - b)/(ac)`
খ. সরল কর: `1/A xx (x - 2)/B + (6x)/C`
গ. প্রমাণ কর যে, `1/A xx (x + 2) -: (x + 2)/C = 1`
Answer ক. নির্ণেয় যোগফল
`= a/(bc) + b/(ca) + c/(ab) + (a - b)/(ac)`
`= (a^2 + b^2 + c^2 + b(a - b))/(abc)`
`= (a^2 + b^2 + c^2 + ab - b^2)/(abc)`
`= (a^2 + ab + c^2)/(abc)` (Ans)
খ. দেওয়া আছে,
A = x - 2
B =` x^2 + 2x + 4`
C =` x^3 - 8`
=` x^3 - 2^3`
=` (x - 2) (x^2 + 2x + 2^2)`
= `(x - 2) (x^2 + 2x + 4)`
প্রদত্ত রাশি,`= 1/A xx (x - 2)/B + (6x)/C`
=` 1/(x - 2) xx 1/(x^2 + 2x + 4) + (6x)/((x - 2) (x^2 + 2x + 4))`
=` 1/(x^2 + 2x + 4) + (6x)/((x - 2)(x^2 + 2x + 4))`
=` (x - 2 + 6x)/((x - 2)(x^2 + 2x + 4))`
=` (7x - 2)/(x^3 - 8)` (Ans)
গ. বামপক্ষ `= 1/A xx (x + 2)/B -: (x + 2)/C`
`= 1/(x - 2) xx (x + 2)/(x^2 + 2x + 4) -: (x + 2)/(x^3 - 8)`
`= (x + 2)/((x - 2) (x^2 + 2x + 4) xx (x^3 - 8)/(x + 2)`
`= (x^3 - 8)/(x^3 - 2^3)`
`= (x^3 - 8)/(x^3 - 8)`
= 1
= ডানপক্ষ
`:. 1/A xx (x + 2)/B -: (x + 2)/C = 1` (প্রমাণিত)