Question

if a+b=1,ab=28,find the value of a^3+b^3​

Answer 1

HEYA ❣️

(a+b)³=a³+b²+3ab(a+b)

PUTTING GIVEN VALUES IN ABOVE IDENTITY.

(1)³=a³+b³+3×28(1)

1=a³+b³+84

1-84=a³+b³

THEREFORE, a³+b³=-83

Answer 2

a^3+b^3=(a+b)^3-3ab(a+b)

=1-3×28=-83