Х(х-25)=0
х₁=0
х₂-25=0
х₂=25
х²(х+7)-(х+7)=(х+7)(х²-1)
х₁+7=0
<em>х₁=-7</em>
х²-1=0
х²=1
<em>х₂=1</em>
<em>х₃=-1</em>
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(9а2-49)*(3а-7-3а+7/(3а+7)(3а-7))=9*60,84-49=547,56-49=498,56
1) a/(a -b) - (a -b)/(a +b) =(a(a+b) -(a-b)(a-b)) /(a-b)(a+b) =(a²+ab -(a²-2ab+b²)) /(a-b)(a+b) =(a²+ab-a²+2ab-b²) /(a-b)(a+b) =(3ab -b²) /(a²-b²)
2) =2(x-y)/y *3y²/(x-y)(x+y) =2(x -y)*3y² /y*(x -y)(x +y) =6y/(x+y)
3) (3v5)² /15 =9*5 /15 =9/3 =3
значок v обозначает корень