(2c²-2b²)/(4b²-8bc+4c²)=2(c²-b²)/4(b²-2bc+c²)=2(c-b)(c+b)/(c-b)²=
=(c+b)/2(c-b)
c=1/3,b=1/4
(1/3+1/4):[2(1/3-1/4)]=7/12:(2*1/12)=7/12:1/6=7/12*6/1=7/2=3,5
(x²+25)/(x-5)³+10x/(5-x)³=(x²+25)/(x-5)³-10x/(x-5)³=(x³+25-10x)/(x-5)³
=(x-5)²/(x-5)³=1/(x-5)
x=5,125
1/(5,125-5)=1/0,125=8
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а) (1 + 3х)(9х² -3х+1)-27х³= 9х² -3х+1 + 27х³ - 9х² +3х+1-27х³ = 2
б)(х+2)(3+х)(3-х)+х²(х+2)=(х+2)(9-х² +х²)=9х+18
в)(х+4)²-9(х-4)²= х²+8х+16-9х²+72х-144=-8х² +80х-128
= 6 + 2√30+5-√120=11+√120-√120=11