几道初一的合并同类项题①n-{n-2+[5m-3(n+2m)+6n]}+2n②½x-2(x-1/3y²)+(-3/2x+1/3y²)③2(t²-t-1)-(t²-t-1)+3(t²-t-1)④-5(2m-n)-6(2n-3m)⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)

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几道初一的合并同类项题①n-{n-2+[5m-3(n+2m)+6n]}+2n②½x-2(x-1/3y²)+(-3/2x+1/3y²)③2(t²-t-1)-(t²-t-1)+3(t²-t-1)④-5(2m-n)-6(2n-3m)⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)

几道初一的合并同类项题①n-{n-2+[5m-3(n+2m)+6n]}+2n②½x-2(x-1/3y²)+(-3/2x+1/3y²)③2(t²-t-1)-(t²-t-1)+3(t²-t-1)④-5(2m-n)-6(2n-3m)⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)
几道初一的合并同类项题
①n-{n-2+[5m-3(n+2m)+6n]}+2n
②½x-2(x-1/3y²)+(-3/2x+1/3y²)
③2(t²-t-1)-(t²-t-1)+3(t²-t-1)
④-5(2m-n)-6(2n-3m)
⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)

几道初一的合并同类项题①n-{n-2+[5m-3(n+2m)+6n]}+2n②½x-2(x-1/3y²)+(-3/2x+1/3y²)③2(t²-t-1)-(t²-t-1)+3(t²-t-1)④-5(2m-n)-6(2n-3m)⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)
①n-{n-2+[5m-3(n+2m)+6n]}+2n
=n-{n-2+[5m-3n-6m+6n]}+2n
=n-{n-2+[3n-m]}+2n
=n-{4n-2-m}+2n
=n-4n+2+m+2n
=2-n+m
②½x-2(x-1/3y²)+(-3/2x+1/3y²)
=½x-2x+2/3y²-3/2x+1/3y²
=½x-2x+2/3y²-3/2x+1/3y²
= - 3x+y²
③2(t²-t-1)-(t²-t-1)+3(t²-t-1)
=(t²-t-1)(2-1+3)
=4(t²-t-1)
④-5(2m-n)-6(2n-3m)
=-10m+5n-12n+18m
=8m-7n
⑤-3(ab-5b²+2a²)-3(7ab+1ba²-25b²)
= -3(ab-5b²+2a²-7ab-1ba²+25b²)
= -3(2a²-6ab-1ba²+20b²)
= -3(2a²-6ab-1ba²+20b²)