Question

8r 2 −5rt+2t 2 8, r, squared, minus, 5, r, t, plus, 2, t, squared from 4r^2+3rt-7t^24r 2 +3rt−7t 2 4, r, squared, plus, 3, r, t, minus, 7, t, squared

Answer 1

`-4r^2 +8rt-9t^2`

Explanation:

We want to subtract
`8r^2 -5rt+2t^2` from
`4r^2+3rt-7t^2`

This is given as:

`4r^2+3rt-7t^2 -(8r^2 -5rt+2t^2)\\`

Open the bracket

`4r^2+3rt-7t^2 -8r^2 +5rt-2t^2\\`

Collect like terms

`4r^2 -8r^2 +5rt+3rt-7t^2-2t^2\\`

Simplify

`=-4r^2 +8rt-9t^2`

Therefore:

`4r^2+3rt-7t^2 -(8r^2 -5rt+2t^2) =-4r^2 +8rt-9t^2`