Replacing x by 4 and y by 2, it is found that the value of the expression is of 8.
The expression given is:
[tex]x(x - y) - y(y^2 - x)[/tex]
We want to evaluate it for x=4 and y=2, hence, we replace x by 4 and y by 2, then:
[tex]4(4 - 2) - 2(2^2 - 4) = 4(2) - 2(0) = 8[/tex]
The value of the expression is of 8.
A similar problem, in which the objective is finding the value of an expression, is given at https://brainly.com/question/19548262