Question 578601
The sum of two numbers is four
a + b = 4
a = (4-b)
:
and their product is one.
a * b = 1
replace a with (4-b)
(4-b)*b = 1
-b^2 + 4b - 1 = 0
Use the quadratic formula to find b
{{{b = (-4 +- sqrt(4^2-4*-1*-1 ))/(2*-1) }}}
{{{b = (-4 +- sqrt(12 ))/(-2) }}}
two solutions:
b = {{{(-4 + 3.464)/(-2) }}} 
b = {{{(-.5358)/(-2)}}}
b = +.268, then a = 3.732
and
{{{b = (-4 - 3.464)/(-2) }}} 
b = {{{(-7.464)/(-2)}}}
b = +3.732, then a = .268
:
Find the sum of their cubes.
.268^3 + 3.732^3 ~ 52