Question

The cube of a number is 8 times the cube of another number. if the sum of the cubes of numbers is 243,what is difference of numbers?

Answer 1

here, a³=8b³
a³+b³=243
8b³+b³=243
b³=27
b=3
a³=8b³
a³=8*27
a³=456

Answer 2

let the numbers be x and y.
x^3 = 8y^3
= x^3 - 8y^3 = 0 ...eq 1
x^3 + y^3 = 243 ....eq2
sub eq 1 and eq 2
-9y^3 = - 243
y^3 = 27
y= 3
substitute y^3 in eq 2
x^3 + 27 = 243
x^3 = 216
x=6
difference is 3