Question

1. 3x^3 + 4xy + 5 when x = 2 and y = 5

Explanation:

Step1: Substitute x and y values

Substitute $x = 2$ and $y = 5$ into $3x^{3}+4xy + 5$. We get $3\times2^{3}+4\times2\times5+5$.

Step2: Calculate the power

First calculate $2^{3}=8$. So the expression becomes $3\times8 + 4\times2\times5+5$.

Step3: Perform multiplications

$3\times8=24$, $4\times2\times5 = 40$. The expression is now $24 + 40+5$.

Step4: Perform additions

$24+40 = 64$, $64 + 5=69$.

Answer:

69