If $ \left(1+2 x+3 x^2\right)^{10}=a_0+a_1 x+a_2 x^2+\ldots+a_{20} x^{20}, $ Then $\mathrm{a}_1$ equ

Question

If $ \left(1+2 x+3 x^2\right)^{10}=a_0+a_1 x+a_2 x^2+\ldots+a_{20} x^{20}, $ Then $\mathrm{a}_1$ equals

Professor PC Thomas Classes · Answer

Expand $\left(1+x(2+3x)\right)^{10} = 1 + 10x(2+3x) + \dots$. Coefficient of $x$ is $20$.