就这四道化简算式初一数学题啊,回答了百分百给分
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就这四道化简算式初一数学题啊,回答了百分百给分
就这四道化简算式初一数学题啊,回答了百分百给分
就这四道化简算式初一数学题啊,回答了百分百给分
（1）原式=-(1/2)*a-a-(2/3)*b平方-(1/2)*a+b平方
=-2*a+(1/3)b平方
（2）原式=4*x-3*y+3*y-x-x+y-5*x
=-3*x+y
（3）原式=5*x平方*y-15*x*y平方-2*x平方*y+14*x*y平方
=3*x平方y-x*y平方
（4）原式=3*m平方-5*m+(1/2)*m-3-2*m平方+4
=m平方-(9/2)*m+4
1.-1/2a-(a+2/3b^2)+(-1/2a+b^2)= -1/2a-a-2/3b^2-1/2a+b^2
= -2a+1/3b
2.(4x-3y)-[-(3y-x)+(x-y)]-5x = (4x-3y)-[-3y+x+x-y]-5x
= (4x-3y...
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1.-1/2a-(a+2/3b^2)+(-1/2a+b^2)= -1/2a-a-2/3b^2-1/2a+b^2
= -2a+1/3b
2.(4x-3y)-[-(3y-x)+(x-y)]-5x = (4x-3y)-[-3y+x+x-y]-5x
= (4x-3y)- (2x-4y)-5x
= 4x-3y-2x+4y-5x
= x+y
3.5(x^2y-3xy^2)-2(x^2y-7xy^2)=(5x^2y-15xy^2)-(2x^2y-14xy^2)
= 5x^2y-15xy^2-2x^2y+14xy^2
= 3x^2y-xy^2
4.3m^2-[5m-(1/2m-3)+2m^2]+4 = 3m^2-[(5m-1/2m+3)+2m^2]+4
= 3m^2-(13/2m+3)+4
= 3m^2-13/2m -3+4
= 3m^2-13/2m+1
收起
（1）原式=-1/2a-a-2/3b²-1/2a+b²
=-2a+1/3b²
(2)原式=4x-3y-(-3y+x-x-y)-5x
=4x-3y+3y-x+x+y-5x
=-x+y
(3)原式=5x²y-15xy²-2x&...
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（1）原式=-1/2a-a-2/3b²-1/2a+b²
=-2a+1/3b²
(2)原式=4x-3y-(-3y+x-x-y)-5x
=4x-3y+3y-x+x+y-5x
=-x+y
(3)原式=5x²y-15xy²-2x²y+14xy²
=3x²y-xy²
(4)原式=3m²-(5m-1/2m+3+2m²)+4
=3m²-5m+1/2m-3-2m²+4
=m²-9/2m+1
收起