1)6△4+8△4=(6*4-6-4)+(8*4-8-4)=(24-10)+(32-12)=14+20=342)7△6-4△5=(7*6-7-6)-(4*5-4-5)=(42-13)-(20-9)=29-11=18
14+22=36 29-11=18 供参考