合并同类项(1)-a+2a+3a+1(2)2a-3b+4﹣2a+5b-2(3)2ax+3by-4xa+3by﹣2ax(4)3x2y-xy2-2x2y+3xy2
题型:解答题难度:一般来源:福建省期中题
合并同类项 (1)-a+2a+3a+1 (2)2a-3b+4﹣2a+5b-2 (3)2ax+3by-4xa+3by﹣2ax (4)3x2y-xy2-2x2y+3xy2 |
答案
解:(1)原式=(﹣1+2+3)a+1 =4a+1; (2)原式=(2﹣2)a+(﹣3+5)b+2 =2b+2; (3)原式=(2﹣4﹣2)ax+(3+3)by =﹣4ax+6by;( 4)原式=(3﹣2)x2y+(﹣1+3)xy2 =x2y+2xy2. |
举一反三
下列合并同类项正确的有 |
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A.2x+4x=8x2 B.3x+2y=5xy C.7x2-3x2=4 D.9a2b-9ba2=0 |
合并同类项:①a﹣2a﹣4a=( ),②a2﹣2(ab﹣b2)﹣b2=( ). |
合并同类项 (1)2x2+1﹣3x+7﹣3x2+5x (2)7xy﹣x2+2x2﹣5xy﹣3x2 |
下面合并同类项正确的是 |
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A.3x+3y=6xy B.2m2n﹣m2n=m2n C.4+5ab=9ab D.7x2﹣5x2=2 |
下面合并同类项正确的是 |
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A.3x+2x2=5x3 B.2a2b﹣a2b=1 C.﹣ab﹣ab=0 D.﹣y2x+xy2=0 |
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