Em chỉ cần mỗi đáp án thôi ạ,ko cần giải chi tiết quá đâu
3. \(\sqrt{4x^2-4x+4}=7x-11\)
<=> \(\sqrt{\left(2x-2\right)^2}=7x-11\)
<=> 2x - 2 = 7x - 11
<=> 11 - 2 = 7x - 2x
<=> 5x = 9
<=> x = \(\dfrac{9}{5}\)
2. \(\dfrac{1}{5}\sqrt{25x+50}-5\sqrt{x+2}+\sqrt{9x+18}+9=0\)
<=> \(\sqrt{25x+50}-\sqrt{x+2}+\sqrt{9x+18}=-9:5:\dfrac{1}{5}\)
<=> \(\sqrt{25x+50-x+2+9x+18}=-9\)
<=> C1: 25x + 50 - x + 2 + 9x + 18 = 81
<=> 25x - x + 9x = 81 - 50 - 2 - 18
<=> 33x = 11
<=> x = \(\dfrac{1}{3}\)
C2: \(\sqrt{25x+50-x+2+9x+18}=\sqrt{81}\)
<=> 25x + 50 - x + 2 + 9x + 18 = 81
Giải tiếp như C1
1, \(\left(2\sqrt{x}+3\right)\left(2\sqrt{x}-1\right)-\sqrt{x}\left(-3+4\sqrt{x}\right)=0\)
<=>\(4x-2\sqrt{x}+6\sqrt{x}-3+3\sqrt{x}-4x=0\)
<=>\(7\sqrt{x}=3\)
<=>\(\sqrt{x}=\dfrac{3}{7}\)
<=>\(x=\dfrac{9}{49}\)
2) \(\dfrac{1}{5}\sqrt{25x+50}-5\sqrt{x+2}+\sqrt{9x+18}+9=0\)
<=>\(\sqrt{x+2}-5\sqrt{x+2}+3\sqrt{x+2}=-9\)
<=>\(-\sqrt{x+2}=-9\)
<=>\(\sqrt{x+2}=9\)
<=>\(x+2=81\)
<=>\(x=79\)
3) \(\sqrt{4x^2-4x+4}=7x-11\)
<=>\(4x^2-4x+4=49x^2-154x+121\)
<=>\(-45x^2+150x-117=0\)
<=>\(x=\dfrac{25+2\sqrt{10}}{15}\) hoặc \(x=\dfrac{25-2\sqrt{10}}{15}\)
