Question

What is the value of (m- n)(n+ m) when m=3 and n= 4?

Answer 1

`\boxed{-7}`

Explanation:

`\sf (m- n)(n+ m)`

`\sf m=3`

`\sf n=4`

___________________

`\sf \left(3-4\right)\left(4+3\right)`

Follow PEMDAS operations:

`\sf \left(3-4\right)`

`\sf =-1`

`\sf \left(4+3\right)`

`\sf =7`

`-1* \:7`

`\sf =-7`