Question

 

Answer 1

c, x=3

d, x=2

Answer 2

\(c,ĐK:x\ge-1\\ PT\Leftrightarrow\sqrt{3x+7}=2+\sqrt{x+1}\\ \Leftrightarrow3x+7=x+5+4\sqrt{x+1}\\ \Leftrightarrow x+1=2\sqrt{x+1}\\ \Leftrightarrow x^2+2x+1=4x+4\\ \Leftrightarrow x^2-2x-3=0\\ \Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=-1\left(tm\right)\end{matrix}\right.\\ d,ĐK:1\le x\le11\\ PT\Leftrightarrow\sqrt{11-x}=2+\sqrt{x-1}\\ \Leftrightarrow11-x=x+3+4\sqrt{x-1}\\ \Leftrightarrow4-x=2\sqrt{x-1}\\ \Leftrightarrow16-8x+x^2=4x-4\\ \Leftrightarrow x^2-12x+20=0\\ \Leftrightarrow\left[{}\begin{matrix}x=10\left(tm\right)\\x=2\left(tm\right)\end{matrix}\right.\)