tìm x :
4 ( x + 1 ) mũ 2 + ( 2x - 1 ) mxu 2 - 8 ( x - 1 ) ( x - 1 ) = 11
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
A . 89 - ( 73 - x ) = 20
73 - x = 89 - 20
73 - x = 69
\(\Rightarrow\)x = 4
B .
Bài 1:
2\(x\) = 4
2\(^x\) = 22
\(x=2\)
Vậy \(x=2\)
Bài 2:
2\(^x\) = 8
2\(^x\) = 23
\(x=3\)
Vậy \(x=3\)
7: \(\left(xy+4\right)^2-\left(2x+2y\right)^2\)
=(xy+4-2x-2y)(xy+4+2x+2y)
=[x(y-2)-2(y-2)][x(y+2)+2(y+2)]
=(x-2)(y-2)(x+2)(y+2)
8: \(81x^2-64y^2=\left(9x\right)^2-\left(8y\right)^2\)
=(9x-8y)(9x+8y)
9: \(\left(a^2+b^2+5\right)^2-4\left(ab+2\right)^2\)
\(=\left(a^2+b^2+5\right)^2-\left(2ab+4\right)^2\)
\(=\left(a^2+b^2+5-2ab-4\right)\left(a^2+b^2+5+2ab+4\right)\)
\(=\left\lbrack\left(a-b\right)^2+1\right\rbrack\left\lbrack\left(a+b\right)^2+9\right\rbrack\)
10: \(\left(x-1\right)^2-\left(x+1\right)^2\)
=(x-1-x-1)(x-1+x+1)
=2x*(-2)=-4x
11: \(8x^3-\frac18=\left(2x\right)^3-\left(\frac12\right)^3=\left(2x-\frac12\right)\left(4x^2+2x\cdot\frac12+\frac14\right)\)
\(=\left(2x-\frac12\right)\left(4x^2+x+\frac14\right)\)
12: \(\frac{1}{25}x^2-64y^2=\left(\frac15x\right)^2-\left(8y\right)^2=\left(\frac15x-8y\right)\left(\frac15x+8y\right)\)
13: \(x^3+\frac{1}{27}=x^3+\left(\frac13\right)^3=\left(x+\frac13\right)\left(x^2-\frac13x+\frac19\right)\)
4.(\(x\) + 1)2 + (2\(x\) - 1)2 - 8.(\(x\) - 1)(\(x-1\) )= 11
4\(x^2\) + 8\(x\) + 4 + 4\(x^2\) - 4\(x\) + 1 - 8\(x^2\) + 16\(x\) - 8 = 11
(4\(x^2\) + 4\(x^2\) - 8\(x^2\)) + (8\(x\) - 4\(x\) + 16\(x\)) + (4 + 1 - 8) = 11
20\(x\) - 3 = 11
20\(x\) = 11 + 3
20\(x\) = 14
\(x\) = \(\dfrac{7}{10}\)