b^{2} -c ^{2} -( b^{2} -2cb)= b^{2} - c^{2} - b^{2} +2cb=2cb- c^{2} =c(2b-c)
(a^-3-а^-3×а^2)÷(а^2×а^-2-а^-2)=а^2÷а^2=1
9x²+82x+9=0
9x²+82x=0-9
9x²+82x=-9
91x³=-9
x=-9
Y=-(25 x^{2} + 10x + 1)+1
Y=-25 x^{2} - 10x - 1+1
Y=-25 x^{2} - 10x
<span>Y=-5(5 x^{2} +2x)
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