A merchant gains or loses, in a bargain, a certain sum

A merchant gains or loses, in a bargain, a certain sum. In a second bargain, he gains 550 dollars, and, in a third, loses 120. In the end he finds he has gained 300 dollars, by the three together. How much did he gain or lose bv the first ?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #32060