① （-2a-b）^2-(3a-2b)^2=4a^2+4ab+b^2-9a^2+12ab-4b^2=-5a^2+16ab-3b^2
② （-1/3t+3）^2+2(1/3t+2)^2=t^2/9-2t+9+2(t^2/9+4t/3+4)=t^2/3+2t/3+17
③ （3a^2+5）(-3a^2+5)-a^2(7a+4)(7a-4)-16a^2=25-9a^4-49a^4+16a^2-16a^2=25-58a^4
④ （x+2y-m）(x+m+2y)=x^2+4yx+4y^2-m^2
⑤( a-1/2)^2(a^2+1/4)^2(a+1/2)^2= ( a-1/2)^2(a+1/2)^2(a^2+1/4)^2=(a^2-1/4)^2(a^2+1/4)^2=(a^4-1/16)^2=a^8-a^4/8+1/256
先化簡,再求值：①(a+b)(a-b)^2-2a^2 .其中a=3,b=1/3
①(a+b)(a-b)^2-2a^2 =(a^2-b^2)(a-b)-2a^2=a^3-ab62-a^2b+b^3-2a^2=6-8/27=154/27
②（3x+2）(3x-2)-5x(x-1)-(2x-1)^2.其中x=1/3
②（3x+2）(3x-2)-5x(x-1)-(2x-1)^2=9x^2-4-5x^2+5x-4x^2+4x-1=9x-5=3-5=-2
后面的不完整,沒有辦法算了