2t²+3t²-(3t²+5t-t²)

问题描述:

2t²+3t²-(3t²+5t-t²)

2t²+3t²-(3t²+5t-t²)=5t²-(2t²+5t)=5t²-2t²-5t=3t²-5t

2t²+3t²-(3t²+5t-t²)
=2t²+3t²-3t²-5t+t²
=3t²-5t