Cho dang dung cua dong tu

a) The two men never (introduce) formally stared at each other across the table

b) There (be) any errors, let me know

c) Where (you\be) all day? I (phone) you dozens of times

So sanh

a \(199^{20}va2003^{15}\)

b \(11^{1979}va37^{1320}\)

c\(63^{17}va17^{26}\)

cho a= \(\sqrt{2}+\sqrt{7+\sqrt[3]{61-46\sqrt{5}}}+1\)

a Cm \(^{a^4-14a^2+9=0}\)

b Giả sử f(x)=\(x^5+2x^4-14x^3-28x^2+9x+19\)

tính f(a)