Question

x^3=891 & y^3=1089 find the value of xy

Answer 1

x³ = 891

y³ = 1089

Find the prime factors:

$891 = 3^4 \times 11$

$1089 = 3^2 \times 11^2$

Find xy:

$xy = ( \sqrt[3]{3^4 \times 11 }\times (\sqrt[3]{3^2 \times 11^2} )$

$xy = \sqrt[3]{3^6 \times 11^3 }$

$xy = 3^2 \times 11$

$xy = 99$

Answer: 99

Answer 2

Here the x^3is of 891 & y^3is of 1089 when wants to find the xy value apply the formula as x^3*y^3 so then the x^3 and y^3 will be calcuated x3 = 891, y3 = 1089, =>x3*y3 = 891*1089 = 970299,

=>xy =∛x3*y3, =>∛970299 = 99 thus when you take cube root you will get the xy value.