Question

Answer 1

a)
\(\sqrt{\left(x-4\right)^2}=2x+7\)
TH1 \(x\ge4\)
=>x-4 = 2x+7
-x=11
x=-11 ( không thỏa mãn )
TH2
x<4
=> -x+4=2x+7
=> -3x=3
=>x=-1
b)
\(5-\sqrt{\left(x-1\right)^2}=0\)
\(-\left|x-1\right|=-5\)
\(\left|x-1\right|=5\)
TH1  x\(\ge1\)
x-1=5
x=6
TH2 x<1
-x+1=5
-x=4
x=-4(ko thỏa mãn)

Answer 2

d: Ta có: \(\sqrt{9x-27}-\dfrac{1}{2}\sqrt{4x-12}+\dfrac{2}{5}\sqrt{25x-75}+\sqrt{x-3}=\sqrt{50}\)

\(\Leftrightarrow\sqrt{25x-75}=\sqrt{50}\)

\(\Leftrightarrow25x-75=50\)

hay x=5