12.50
12.75
12.25
12.00
Given:-(x+10)50+(x饡挼0)50=a0+a1x+a2x2+...+a50x50To find:-a2a0=coefficient of x2Coefficient of x0As we know that, the general term in an expansion(a+b)nis given as,Tr+1=nCr(a)n鈭抮(b)rNow,General term of(x+10)50-Here,a=x,b=10Tr+1=50Cr(x)50鈭抮(10)rFor coefficient ofx2-50鈭抮=2鈬抮=48T48+1=50C48(x)50髷几(10)48T49=50C48(10)48x2For coeficient ofx0-50鈭抮=0鈬抮=50T50+1=50C50(x)50髷己(10)50T51=50C50(10)50x0Now,General term of(x+(饡挼0))50-Here,a=x,b=饡挼0Tr+1=50Cr(x)50鈭抮(饡挼0)rFor coeficient ofx2-50鈭抮=2鈬抮=48T48+1=50C48(x)50髷几(饡挼0)48T49=50C48(10)48x2For coeficient ofx0-50鈭抮=0鈬抮=50T50+1=50C50(x)50髷己(饡挼0)50T51=50C50(10)50x0Now from the given expansion,a2=50C48(10)48+50C48(10)48=50C48((10)48+(10)48)a0=50C50(10)50+50C50(10)50=50C50((10)50+(10)50)Now,a2a0=50C48((10)48+(10)48)50C50((10)50+(10)50)As we know that,nCr=n!r!(n鈭抮)!Therefore,a2a0=50脳492脳(10481050)鈬抋2a0=494=12.25