Question

How do you simplify `(-t+15t^2)-(5t^2+2t-9)`?

Answer 1

Simply change the sign to the last three terms and add the same power of `t`:
`-t+15t^2-(5t^2+2t−9)= -t+15t^2-5t^2-2t+9`
Now, you can sum up the two squares: `15t^2-5t^2=10t^2`,
the linear coefficient: `-t-2t=-3t`,
and obtain the expression `10t^2-3t+9`