Question:`p = a^2 + 3a - 4, Q = a^2 - 1, R = a^2 + 5a + 4`
ক. p এর উৎপাদক কতটি?
খ. P Q R এর ল,সা,গু নির্ণয় কর।
গ. সরল কর: `(3a)/P + (2a)/Q + a/(a^2 + 5a + 4)`
Answer ক দেওয়া আছে,
`P = a^2 + 3a - 4`
`= a^2 + 4a - a - 4`
`= a (a + 4) - 1(a + 4)`
= (a + 4) (a - 1)
সুতরাং p এর উৎপাদক 2টি।
খ. ‘ক’ থেকে পাই,
p = (a + 4) (a - 1)
দেওয়া আছে, Q =` a^2 - 1`
= (a + 1) (a - 1)
এবং R` = a^2 + 5a + 4`
=` a^2 + 4a + a + 4`
=` a(a + 4) + 1(a + 4)`
=` (a + 4) (a + 1)`
:. P, Q, R এর ল,সা,গু
= (a + 4) (a - 1) (a + 1)
= `(a + 4) (a^2 - 1)`
গ. প্রদত্ত রাশি
`= (3a)/(a^2 + 3a - 4) + (2a)/(a^2 - 1) + a/(a^2 + 5a + 4)`
`= (3a)/(a^2 + 4a - a - 4) + (2a)/((a + 1)(a - 1)) + a/(a^2 + a + 4a + 4)`
`= (3a)/((a + 4)(a - 1)) + (2a)/((a + 1)(a - 1)) + a/((a + 1)(a + 4))`
`= (3a(a + 1) + 2a(a + 4) + a(a - 1))/((a + 4)(a + 1)(a - 1))`
`= (3a^2 + 3a + 2a^2 + 8a + a^2 - a)/((a + 4)(a + 1)(a - 1))`
`= (6a^2 + 10a)/((a + 4)(a + 1)(a - 1))`
`= (2a(3a + 5))/((a + 4)(a^2 - 1))`