Các câu hỏi tương tự
Phương pháp 3. Sử dụng phép đặt ẩn phụ
a \(3x^2+21x+18+2\sqrt{x^2+7x+7}=2\)
b \(x^2-6x+9=4\sqrt{6-6x+x^2}\)
c \(\sqrt{\dfrac{x^2+x+1}{x}}+\sqrt{\dfrac{x}{x^2+x+1}}=\dfrac{7}{4}\)
d \(x^2+8x-3=2\sqrt{x\left(8+x\right)}\)
6/ \(x+2+4\sqrt{x^2-x+2}=2\sqrt{6x^2-x+14}\)
7/ \(\sqrt{2x^2+x+1}+\sqrt{x^2-x+1}=3x\)
8/ \(\frac{x}{\sqrt{x+2}}+\sqrt{x+1}=\sqrt{3x+1}\)
9/ \(\sqrt{9x^2-8x+1}+3\sqrt{x^2-x+1}=8-x\)
Giải phương trình:
a.\(\left(17-6x\right)\sqrt{3x-5}+\left(6x-7\right)\sqrt{7-3x}=2+8\sqrt{36x-9x^2-35}\)
b.\(\sqrt{x^2-3x+2}=\sqrt{10x-20}-\sqrt{x-3}\)
21 tháng 9 2017 lúc 18:04
Tìm X:
Bài 1:
\(\sqrt[3]{x-8}+\sqrt{x+7}+x^3-8x^2-8x-14=0\)
Bài 2
\(\sqrt{x+3}+\sqrt{x+8}+x^2+3x-9=0\)
\(\sqrt{6x^2-8x+2}+2\sqrt{x+3}-3x=5\)
Giải các phương trình dưới đây
1, \(\sqrt{9x^2-6x+2}+\sqrt{45x^2-30x+9}=\sqrt{6x-9x^2+8}\)
2,\(\sqrt{2x^2-4x+3}+\sqrt{3x^2-6x+7}=2-x^2+2x\)
3, \(\sqrt{6y-y^2-5}-\sqrt{x^2-6x+10}=1\) (x=3 ; y=3)
\(\left(5\right)\sqrt{x+3-4\sqrt{x-1}}\sqrt{x+8+6\sqrt{x-1}}=5\)
\(\left(6\right)2x^2+3x+\sqrt{2x^2+3x+9}=33\)
\(\left(7\right)\sqrt{3x^2+6x+12}+\sqrt{5x^4-10x^2+30}=8\)
\(\left(8\right)x+y+z+8=2\sqrt{x-1}+4\sqrt{y-2}+6\sqrt{z-3}\)
Giải phương trinh:
a) \(\sqrt{4+2x-x^2}=x-2\)
b) \(\sqrt{x+3-4\sqrt{x-1}}+\sqrt{x+8+6\sqrt{x-1}}=1\)
c) \(\sqrt{3x^2+6x+7}+\sqrt{5x^2+10x+14}=4-2x-x^2\)
d) \(\sqrt{x-3}+\sqrt{5-x}=x^2-8x+18\)
giải phương trình:
\(\sqrt{2x^2-4x+3}+\sqrt{3x^2-6x+7}=8x-4x^2-1\)
Pleft(xright)sqrt[3]{sqrt{x+8}left(x^4+8x^3+12xright)+6x^3+48x^2+8}đặt Asqrt{x+8}left(x^4+8x^3+12xright)+6x^3+48x^2+8 sqrt{x+8}left(x^4+8x^3right)+6x^2left(x+8right)+12xsqrt{x+8}+8 sqrt{left(x+8right)^3}x^3+3sqrt{left(x+8right)^2}x^22+3sqrt{left(x+8right)}x4+8 left(xsqrt{x+8}+2right)^3Rightarrow Pleft(xright)xsqrt{x+8}+2
Đọc tiếp
\(P\left(x\right)=\sqrt[3]{\sqrt{x+8}\left(x^4+8x^3+12x\right)+6x^3+48x^2+8}\)
đặt \(A=\sqrt{x+8}\left(x^4+8x^3+12x\right)+6x^3+48x^2+8\)
\(=\sqrt{x+8}\left(x^4+8x^3\right)+6x^2\left(x+8\right)+12x\sqrt{x+8}+8\)
\(=\sqrt{\left(x+8\right)^3}x^3+3\sqrt{\left(x+8\right)^2}x^22+3\sqrt{\left(x+8\right)}x4+8\)
\(=\left(x\sqrt{x+8}+2\right)^3\)
\(\Rightarrow P\left(x\right)=x\sqrt{x+8}+2\)