Question

Evaluate the expression for the given variable values. 3 |m + 2n|² -(mn)² if m = 3 and n = -5-1212794-78

Answer 1

We have the expression:

$3|m+2n|^2-(mn)^2$

We have to evaluate it for m = 3 and n = -5.

To do that we replace the variables with its values and calculate:

$\begin{gathered} 3|m+2n|^2-(mn)^2 \\ 3|3+2(-5)|^2-(3\cdot(-5))^2 \\ 3|3-10|^2-(-15)^2 \\ 3|-7|^2-225 \\ 3\cdot7^2-225 \\ 3\cdot49-225 \\ 147-225 \\ -78 \end{gathered}$

Answer: the value of the expression is -78.