Keep doing each step manually, and see where it slips up:
−7.9+8.2−3.4+2.1=−1
−7.9+8.2+(−3.4)+2.1=−1
−7.9+(−3.4)+8.2+2.1=−1
(−7.9+(−3.4))+(8.2+2.1)=−1
−11.3+10.3=−1
First you have multiply 6 by both 3x and 8 6*3x = 18x 6*8= 48 18x + 48 + 32 + 12x now combine like terms 18x + 12x = 30x 48 + 32 = 80 so 30x + 80 is your answer
