Question

What should be subtracted from –7mn + 2m² + 3n² to get m² + 2mn + n²?

Answer 1

In order to get solution, we will subtract m² + 2mn + n² from –7mn + 2m² + 3n²

Required expression is –7mn + 2m² + 3n² – (m² + 2mn + n²) = –7mn + 2m² + 3n² – m² – 2mn – n²

On combining the like terms,

= –7mn – 2mn + 2m² – m² + 3n² – n²

= –9mn + m² + 2n²

So, if we subtract m² + 2n² – 9mn from –7mn + 2m² + 3n², then we get m² + 2mn + n².