Question

How do I subtract 4m^2 + 2mn + 8n^2 from 2m^2 + 6mn + 2n^2 ?

Answer 1

$-2m^2+4mn-6n^2$

1) Let's write out both expressions subtracting 4m²+2mn+8n² from 2m²+6mn+2n²

$\begin{gathered} 2m^{2}+6mn+2n^{2}-(4m^{2}+2mn+8n^2)_{} \\ 2m^2+6mn+2n^2-4m^2-2mn-8n^2 \\ -2m^2+4mn-6n^2 \end{gathered}$

2) Note that when we subtract 4m^2 + 2mn + 8n^2 from 2m^2 + 6mn + 2n^2 we need to swap the sign by placing -1 outside the parentheses and then combine like terms adding those terms algebraically.