AP EAMCET202418 May 2024Morning ShiftMathematicsBinomial TheoremActual
The square root of independent term in the expansion of ( 2 x^2 5 + 5 x )¹⁰ is
Options
- A15 10
- B10 15
- C30 5
- D20 5
Correct answer
C. 30 5
Step-by-step solution
Since the general term in the expansion is ( 2 x^2 5 + 5 x )¹⁰ T _ r+1 = ¹⁰ C _r ( 2 x^2 5 )^ 10-r ( 5^ 1 2 x^ 1 2 )^r= ¹⁰ C _r 2^ 10-r x^ 20-2 r- r 2 5^ 10-r- r 2 for independent of x, 20-2 r- r 2 =0 r=8 So, T ₉= ¹⁰ C ₈ 2^2 5⁻² = 10 9 2 4 5^2=5^3 3^2 2^2 Now, T₉ = 5^3 3^2 2^2 =5 3 2 5 =30 5