因式分解數學

a. -1+x-w(1-x)
=-1+x-w+wx
=(x-1)+w(x-1)
=(x+1)(x-1)
b.8(p-q)(3x-2y)+10(q-p)(2y-5z)
=8(p-q)(3x-2y)-10(-q+p)(2y-5z)
=2(p-q)(4(3x-2y)-5(2y-5z))
c.7x/(2a-b)+3x/(2b-4a)
=14x/(4a-2b)-3x/(4a-2b)
=11x/(4a-2b)
d. A=2r+S/9 {S}
A-2r=S/9
S=9A-18r
e. y=1/2(a-x/x+b) {x}
2y=a-x/x+b
2xy+2by=a-x
2by-a=-x-2xy
-(a-2by)=-x(1+2y)
x=(a-2by)/(1+2y)
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