Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(a.x\left(x-5\right)\left(x+5\right)-\left(x+2\right)\left(x^2-2x+4\right)=3\)
\(\Leftrightarrow x\left(x^2-5^2\right)-\left(x^3+2^3\right)=3\)
\(\Leftrightarrow x^3-25x-x^3-8=3\)
\(\Leftrightarrow x^3-x^3-25x=8+3\)
\(\Leftrightarrow x=\frac{11}{-25}\)
Vậy x có nghiệm là \(\frac{-11}{25}.\)
\(\)
\(12\left(x-2\right)\left(x+2\right)-3\left(2x+3\right)^2\)=52\(\Leftrightarrow12\left(x^2-2^2\right)-3\left(4x^2+12x+9\right)=52\)
\(\Leftrightarrow12x^2-48-12x^2-36x-27-52=0\)
\(\Leftrightarrow-36x-127=0\)
\(\Leftrightarrow x=-3.52\)
Bạn học hằng đẳng thức chưa bạn , bạn chỉ cần nắp chúng vào là làm đc thôi
a. x ( x + 4 ) ( 4 - x ) + ( x - 5 ) ( x2 + 5x + 25 ) = 3
- x ( x + 4 ) ( x - 4) + x3 - 53 = 3
-x . (x2 - 42) + x3 -125 = 3
-x3 + 16x + x3 - 125 = 3
16x - 125 = 3
16x = 128
x =8
\(12\left(x-2\right)\left(x+2\right)-3\left(2x+3\right)^2\) \(=52\)
\(12\left(x^2-4\right)-3\left(4x^2+12x+9\right)\) \(=52\)
\(12x^2-48-12x^2-36x-27\) \(=52\)
\(-36x-75=52\)
\(-36x=127\)
\(x=\frac{-127}{36}\)
\(\left(2x+1\right)^2-4\left(x-1\right)\left(x+1\right)\) \(+2x=5\)
\(4x^2+4x+1-4\left(x^2-1\right)\) \(+2x=5\)
\(4x^2+4x-1-4x^2+4+2x=5\)
\(6x+3=5\)
\(6x=2\)
\(x=3\)
\(\left(x-2\right)^3-\left(x-3\right)\left(x^2+3x+9\right)\) \(+6\left(x-1\right)^2=15\)
\(x^3-6x^2+12x-8-\left(x-3\right)\left(x+3\right)^2\) \(+6\left(x^2-2x+1\right)=15\)
\(x^3-6x^2+12x-8-\left(x^2-9\right)\left(x+3\right)\) \(+6x^2-12x+6=15\)
\(x^3-2\) \(-\left(x^3+3x^2-9x-27\right)\)\(=15\)
\(x^3-2-x^3-3x^2+9x+27=15\)
\(-3x^2+9x+25=15\)
\(-3x^2+9x+10=0\)
\(-3\left(x^2-3x-\frac{10}{3}\right)\) \(=0\)
\(x=\frac{9+\sqrt{201}}{6}\)
các câu còn lại tương tự
a) \(\left(x-3\right)\left(x+3\right)=\left(x-2\right)^2-1\)
\(\Leftrightarrow x^2-9=x^2-4x+4-1\)
\(\Leftrightarrow4x=12\)
\(\Leftrightarrow x=3\)
b) \(\left(2x-1\right)^2=\left(2x+5\right)\left(2x-5\right)+2\)
\(\Leftrightarrow4x^2-4x+1=4x^2-25+2\)
\(\Leftrightarrow4x=24\)
\(\Leftrightarrow x=6\)
c) \(\left(x+1\right)^3=x^2\left(x-2\right)+5\left(x^2-1\right)\)
\(\Leftrightarrow x^3+3x^2+3x+1=x^3-2x^2+5x^2-5\)
\(\Leftrightarrow3x=-6\)
\(\Leftrightarrow x=-2\)
d) \(\left(x^2-3x+9\right)\left(x+3\right)=\left(x-2\right)^3+\left(3x-1\right)\left(2x+3\right)\)
\(\Leftrightarrow x^3+3^3=x^3-6x^2+12x-8+6x^2+7x-3\)
\(\Leftrightarrow x^3+27=x^3+19x-11\)
\(\Leftrightarrow19x=38\)
\(\Leftrightarrow x=2\)
\(a)6\left(x+2\right)\left(x-3\right)-3\left(x-2\right)^2-3\left(x-1\right)\left(x+1\right)=1\\ \Leftrightarrow\left(6x+12\right)\left(x-3\right)-3\left(x^2-4x+4\right)-3\left(x^2-1\right)=1\\ \Leftrightarrow6x^2-18x+12x-36-3x^2+12x-12-3x^2+3=1\\ \Leftrightarrow6x-45=1\\ \Leftrightarrow6x=1+45\\ \Leftrightarrow6x=46\)
\(\Leftrightarrow\)\(x=\dfrac{23}{3}\)
\(b)\left(x-1\right)\left(x^2+x+1\right)+x\left(x+2\right)\left(2-x\right)=5\\ \Leftrightarrow x^3-1+x\left(4-x^2\right)=5\\ \Leftrightarrow x^3-1+4x-x^3=5\\ \Leftrightarrow4x=5+1\\ \Leftrightarrow4x=6\)
\(\Leftrightarrow\)\(x=\dfrac{3}{2}\)