Question

What is the value of the expression below when x=4 and y=3?
The question is 5x to the 3rd power plus 4y to the 3rd power

Answer 1

$x = 4\\y = 3$

Question is $5x^3 + 4y^3$

We know what $x$ and $y$ are.

$5x^3 + 4y^3 = 5 \times 4^3 + 4 \times 3^3\\= 5 \times 64 + 4 \times 27\\= 320 + 108\\= 428$