a) ĐKXĐ: x <= 2
pt --> 4 - 2x = 25 <=> x = -21/2 (thỏa)
b) ĐKXĐ: x >= -1
pt <=> 8sqrt(x + 1)=16 <=> sqrt(x+1)=2 --> x + 1 = 4 <=> x = 3
c) pt <=> |2x+3|=4
TH1: 2x+3=4 <=> x=1/2
TH2: 2x+3=-4 <=> x=-7/2
\(a.\sqrt{4-2x}=5\) Đk x<=2
\(4-2x=25\)
\(2x=-21\)
\(x=-\dfrac{21}{2}\)
b) \(\sqrt{25\left(x+1\right)}+\sqrt{9x+9}=16\) ĐK x>=-1
\(5\sqrt{x+1}+3\sqrt{x+1}=16\)
\(\sqrt{x+1}=2\)
\(x+1=4\Leftrightarrow x=3\)
c)\(4x^2+12x+9=16\)
\(4x^2+12x-7=0\)
\(\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=-\dfrac{7}{2}\end{matrix}\right.\)