代数式化简专项训练(带答案)(4 页)Good is good, but better carries it
精益求精,善益求善
代数式化简专项训练1、3a2﹣2a+4a2﹣7a 2、3(x﹣3y)﹣2(y﹣2x)﹣x =7a2﹣9a =6x﹣11y3、(7y﹣3z)﹣(8y﹣5z) 4、﹣4x2y+8xy2﹣9x2y﹣21xy2=2z﹣y =﹣13x2y﹣13xy25、3x2﹣1﹣2x﹣5+3x﹣x2 6、5m2﹣[+5m2﹣(2m2﹣mn)﹣7mn﹣5] =2x2+x﹣6 =2m2+6mn+57、21a+8(b2+a2)﹣8(a2+b2﹣3a) 8、3a2b+2ab2﹣5﹣3a2b﹣5ab2+2 =45a =﹣3ab2﹣3 9、(x+y)(x﹣y)﹣x(x﹣y)﹣xy 10、2x2﹣(﹣x2+3xy+2y2)﹣(x2﹣xy+2y2) =﹣y2 =2x2﹣2xy﹣4y2 11、2(x﹣y)2﹣3(x﹣y)+5(y-x)2+3(y-x) 12、2x2﹣{﹣3x+[4x2﹣(3x2﹣x)]} =7(x﹣y)2﹣6(x﹣y) =x2+2x13、3x(x﹣2y)﹣[3x2﹣2y+2(xy+y)] 14、7a2b+(﹣4a2b+5ab2)﹣(2a2b﹣3ab2) =﹣8xy =a2b+8ab215、3x2y﹣[2x2﹣(xy2﹣3x2y)﹣4xy2] 16、x﹣2(x﹣y2)+(﹣x+y2)=5xy2﹣2x2 =﹣3x+y217、﹣2(mn﹣3m2)﹣[m2﹣5(mn﹣m2)+2mn] =mn 18、x2+(2xy﹣3y2)﹣2(x2+xy﹣2y2) =﹣x2+y219、(a2+1)﹣3a(a﹣1)+2(a2+a﹣1) 20、8a2b+2(2a2b﹣3ab2)﹣3(4a2b﹣ab2) =5a﹣1 =﹣3ab221、2x2﹣[7x﹣(4x﹣3)+2x2] 22、2(3x2﹣2xy)﹣