\(=\frac{\left(147-47\right)^2}{\left(125-25\right)\left(125+25\right)}\)

\(=\frac{100^2}{100.150}\) \(=\frac{100}{150}=\frac{2}{3}\)

\(=\frac{147^2-2.47.147+47^2}{\left(125+25\right)\left(125-25\right)}=\frac{\left(147-47\right)^2}{150.100}=\frac{100^2}{150.100}=\frac{100}{150}=\frac{2}{3}.\)

2.000 VND bán ko 

\(\sqrt{9x-18}+\sqrt{x-2}=16\)

\(\Rightarrow\sqrt{9x-18}=16-\sqrt{x-2}\)

\(\Rightarrow9x-18=256-32\sqrt{x-2}+x-2\)

\(\Rightarrow9x-x=272-\sqrt{x-2}\)

\(\Rightarrow\sqrt{x-2}=272-8x\)

\(\Rightarrow x-2=73984-4352x+64x^2\)

\(\Rightarrow64x^2-4353x+7386=0\)

Làm nốt

a) (5x-1)²-(5x-4)(5x+4)=7

    \(25x^2-10x+1-\left(25x^2+20x-20x-16\right)=7\)

\(25x^2-10x+1-25x^2-20x+20x+16=7\)

\(-10x=7-1-16\)

\(-10x=-10\)

\(x=1\)

b) (x+5)²-x²=45

\(x^2+10x+25-x^2=45\)

\(10x=45-25\)

\(10x=20\)

\(x=2\)

Học tốt !!! có gì ko hiểu thì họi lại nhé em 

a) (5x - 1)² - (5x - 4)(5x + 4) = 7

25x² - 10x + 1 - 25x² + 16 = 7

-10x + 17 = 7

-10x = 7 - 17

-10x = -10

x = 1

b) (x + 5)² - x² = 45

x² + 10x + 25 - x² = 45

10x + 25 = 45

10x = 45 - 25

10x = 20

x = 2

Ko rút gọn được

cảm ơn bạn nha

\(=\left(163+37\right)^2\) \(=200^2\) \(=40000\)

163² + 74 . 163 + 37² = ( 163 + 37 ) . ( 163 + 37 ) = 200 . 200 = 40000