This is basically saying that 125 + 170 +x = 180. 125 + 170 = 295. 295 + x = 180. We rearrange the expression so that 295 - 180 = -x, so -x = 115, x = -115. Ask if you have any questions.
This is basically saying that 125 + 170 +x = 180. 125 + 170 = 295. 295 + x = 180. We rearrange the expression so that 295 - 180 = -x, so -x = 115, x = -115. Ask if you have any questions.