\(\frac{x^2+25y^2}{x^2-25y^2}-\frac{10xy}{x^2-25y^2}\)
Tính
a, \(\dfrac{x}{2y^2-xy}+\dfrac{4y}{x^2-2xy}\)
b, \(\dfrac{x+1}{2x-2}+\dfrac{-2x^2+3}{3x^2-3}\)
c,\(\dfrac{x^2+4x+4}{x^2-10xy+25y^2}.\dfrac{x^2-25y^2}{x^2-4}\)
c: \(=\dfrac{\left(x+2\right)^2}{\left(x-5y\right)^2}\cdot\dfrac{\left(x-5y\right)\left(x+5y\right)}{\left(x-2\right)\left(x+2\right)}\)
\(=\dfrac{\left(x+2\right)\left(x+5y\right)}{\left(x-5y\right)\left(x-2\right)}\)
25-x^2-10xy-25y
\(25-x^2-10xy-25y^2\)
\(=25-x^2-10xy-25y^2\)
\(=25-\left(x^2+10xy+25y^2\right)\)
\(=25-\left(x+5y\right)^2\)
\(=5^2-\left(x+5y\right)^2\)
\(=\left(5-x-5y\right)\left(5+x+5y\right)\)
Sửa đề: 25-x^2-10xy-25y^2
=25-(x^2+10xy+25y^2)
=25-(x+5y)^2
=(5-x-5y)(5-x+5y)
10xy-25y^2-x^2
Làm rõ ràng hộ mình ạ:))
\(=-\left(x^2-10xy+25y^2\right)=-\left(x-5\right)^2\)
\(10xy-25y^2-x^2\)
\(-x^2+10xy-25y^2\)
\(-\left[x^2-10xy+25y^2\right]\)
\(-\left[x^2-2x5y+\left(5y\right)^2\right]\)
\(-\left(x-5y\right)^2\)
phân tích đa thức thành nhân tử : x^2+3zt(2-3zt)-10xy-1+25y^2
tính giá trị của biểu thức :
x^2-10xy+25y^4 tại x = 105 , y = 5
\(x^2-10xy+25y^4\\ =x^2-2.5.x.y+\left(5y^2\right)^2\\ =\left(x-5y^2\right)^2\)
Thay \(x=105,y=5\) vào biểu thức ta được:
\(\left(105-5.5^2\right)^2\\ =\left(105-5.25\right)^2\\ =\left(-23\right)^2\\ =529\)
x^2-10xy+25y^4 = (x-5y)^2
thay x=105, y=5 ta được (105-5.5)^2=80^2=6400
chuyển tổng thành tích x2-10xy+25y2
Điền vào chỗ chấm
a) x^2 + 6xy+...= (...+3y)^2
b) ...- 10xy + 25y^2 = (...-...)^2
\(\left(\frac{5x+y}{x^2-5xy}+\frac{5x-y}{x^2+5xy}\right).\frac{x^2-25y^2}{x^2+y^2}\)
\(\left(\frac{5x+y}{x^2-5xy}+\frac{5x-y}{x^2+5xy}\right).\frac{x^2-25y^2}{x^2+y^2}\)
\(=\left(\frac{5x+y}{x\left(x-5y\right)}+\frac{5x-y}{x\left(x+5y\right)}\right).\frac{\left(x-5y\right)\left(x+5y\right)}{x^2+y^2}\)
\(=\frac{\left(5x+y\right)\left(x+5y\right)+\left(5x-y\right)\left(x-5y\right)}{x\left(x-5y\right)\left(x+5y\right)}.\frac{\left(x-5y\right)\left(x+5y\right)}{x^2+y^2}\)
\(=\frac{10\left(x^2+y^2\right)}{x\left(x^2+y^2\right)}=\frac{10}{x}\)
\(\left(\frac{5x+y}{x^2-5xy}+\frac{5x-y}{x^2+5xy}\right).\frac{x^2-25y^2}{x^2+y^2}\)
\(=\left(\frac{5x+y}{x\left(x-5y\right)}+\frac{5x-y}{x\left(x+5y\right)}\right)\frac{\left(x-5y\right)\left(x+5y\right)}{x^2+y^2}\)
\(=\frac{\left(5x+y\right)\left(x+5y\right)+\left(5x-y\right)\left(x-5y\right)}{x\left(x-5y\left(x+4y\right)\right)}.\frac{\left(x-5y\right)\left(x+5y\right)}{x^2+y^2}\)
\(=\frac{10\left(x^2+y^2\right)}{x\left(x^2+y^2\right)}=\frac{10}{x}\)
a ) x2 - 10xy + 25y2
x2 - 10xy + 25y2
= x2 - 10xy + (5y)2
= ( x -5y )2
\(x^2-10xy+25y^2\)
\(\Rightarrow x^2-10xy+\left(5y^2\right)\)
\(\Rightarrow\left(x-5y\right)^2\)
Code : Breacker