Tìm x:(x-1)(x+1)(x+3)(x+5)= -16
Giải giúp m trong tối nay luôn nha
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
x + \(\frac{1}{3}\)= \(\frac{2}{5}\)
=> x = \(\frac{2}{5}\)- \(\frac{1}{3}\)
=> x = \(\frac{1}{15}\)
Bài giải
a, \(-\left(-x\right)-\left(-9\right)=-\left(3-6-9+3\right)\)
\(x+9=-3+6+9-3\)
\(x+9=15\)
\(x=15-9\)
\(x=6\)
b, \(17-x=7-6x\)
\(6x-x=7-17\)
\(5x=-10\)
\(x=-10\text{ : }5\)
\(x=-2\)
c, \(5x-7=-21-2x\)
\(5x+2x=-21+7\)
\(7x=-14\)
\(x=-14\text{ : }7\)
\(x=-2\)
d, \(7\left(x-3\right)-5\left(3-x\right)=11x-5\)
\(7x-21-15+5x=11x-5\)
\(7x+5x-11x=21+15-5\)
\(x=31\)
\(x\inƯ\left(63\right)\)
\(Ư\left(63\right)=\left\{1;3;7;9;21;63\right\}\)
\(x+1\inƯ\left(63\right)\Rightarrow x=1-1=0\)
\(x=3-2=1\)
\(x=7-1=6\)
\(x=9-8=1\)
\(x=21-1=20\)
\(x=63-1=62\)
\(\Rightarrow x\in\left\{0;2;6;8;20;62\right\}\)
\(a,2.\left(x+3\right)-3x=-2x+7\)
\(\Leftrightarrow2x+6-3x=-2x-7\)
\(\Leftrightarrow-x+6=-2x+7\)
\(\Leftrightarrow x=-6+7\)
\(\Leftrightarrow x=1\)
\(b,5.\left(x-3\right)-29=-2.\left(7-x\right)-23\)
\(\Leftrightarrow5x-15-29+23=14-2x\)
\(\Leftrightarrow5x-21=14-2x\)
\(\Leftrightarrow5x+2x=35\)
\(\Leftrightarrow x=5\)
\(c,-17+\left|5-x\right|=-2.7\)
\(\Leftrightarrow-17+\left|5-x\right|=-14\)
\(\Leftrightarrow\left|5-x\right|=3\)
\(\Leftrightarrow\orbr{\begin{cases}5-x=3\\5-x=-3\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=8\end{cases}}\)
\(d,21-\left|x+7\right|=-42:\left(-2\right)\)
\(\Leftrightarrow21-\left|x+7\right|=21\)
\(\Leftrightarrow\left|x+7\right|=0\)
\(\Leftrightarrow x+7=0\)
\(\Leftrightarrow x=7\)
\(f,\left|3x-5\right|-\left(-15\right)=5\)
\(\Leftrightarrow\left|3x-5\right|+15=5\)
\(\Leftrightarrow\left|3x-5\right|=-10\)
Vì \(\left|a\right|\ge0\)mà \(-10< 0\)nên \(x\in\Phi\)
Đã giải quyết xong!!!
giúp mình với: so sánh -37/56 với -377/567 ai giải đc mình cho
b, pt \(\Leftrightarrow\)mx - 2=0
Nếu m=0 pt\(\Leftrightarrow\) -2=0 (vô lí)\(\Rightarrow\)m=2(loại)
Nếu m\(\ne\)0 pt có nghiệm x=\(\dfrac{2}{m}\)
B = \(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{5}\right)x........x\left(1-\frac{1}{2003}\right)x\left(1-\frac{1}{2004}\right)\)
B = \(\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x\frac{4}{5}x.........x\frac{2002}{2003}x\frac{2003}{2004}\)
=> B = \(\frac{1}{2004}\)
\(B=\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times...\times\left(1-\frac{1}{2003}\right)\times\left(1-\frac{1}{2004}\right)\)
\(B=\frac{1}{2}\times\frac{2}{3}\times\frac{3}{4}\times...\times\frac{2002}{2003}\times\frac{2003}{2004}\)
\(B=\frac{1\times2\times3\times...\times2002\times2003}{2\times3\times4\times...\times2003\times2004}\)
\(\Rightarrow B=\frac{1}{2004}\)
a)\(ĐKXĐ:x\ne m;x\ne2\)
\(\frac{x+1}{m-x}=\frac{x+4}{x-2}\)
\(\Leftrightarrow\left(m-x\right)\left(x+4\right)=\left(x+1\right)\left(x-2\right)\)
\(\Leftrightarrow-x^2+\left(m-4\right)x+4m=x^2-x-2\)
\(\Leftrightarrow-2x^2+\left(m-3\right)x+\left(4m+2\right)=0\)
Để phương trình vô nghiệm thì \(\Delta< 0\)
hay \(\left(m-3\right)^2-4.\left(-2\right).\left(4m+2\right)< 0\)
\(\Leftrightarrow m^2-6m+9+32m+16< 0\)
\(\Leftrightarrow m^2+26m+25< 0\)
\(\Leftrightarrow m^2+26m+169-144< 0\)
\(\Leftrightarrow\left(m+13\right)^2< 144\)
\(\Leftrightarrow\orbr{\begin{cases}m+13< 12\\m+13>-12\end{cases}}\Leftrightarrow\orbr{\begin{cases}m< -1\\m>-25\end{cases}}\)
b) \(ĐKXĐ:x\ne m;x\ne1\)
\(1+\frac{2x+1}{m-x}=\frac{3x-5}{x-1}\)
\(\Leftrightarrow\frac{x+1+m}{m-x}=\frac{3x-5}{x-1}\)
\(\Leftrightarrow\left(x+1+m\right)\left(x-1\right)=\left(3x-5\right)\left(m-x\right)\)
\(\Leftrightarrow x^2+mx-m-1=3xm-5m-3x^2+5x\)
\(\Leftrightarrow4x^2-\left(2m+5\right)x+\left(4m-1\right)=0\)
Để phương trình vô nghiệm thì \(\Delta< 0\)
\(\Rightarrow\left(2m+5\right)^2-4.4.\left(4m-1\right)=4m^2-44m+41< 0\)
\(\Rightarrow4m^2-44m+121-80< 0\)
\(\Rightarrow\left(2m-11\right)^2< 80\)
\(\Rightarrow\orbr{\begin{cases}2m-11< \sqrt{80}\\2m-11>-\sqrt{80}\end{cases}}\)
Vậy \(\orbr{\begin{cases}m< \frac{\sqrt{80}+11}{2}\\m>-\frac{\sqrt{80}+11}{2}\end{cases}}\)
Tập xác định của phương trình
\(x\in\left(\infty;-\infty\right)\)
Lời giải thu được
\(-\sqrt{5}-2\)
\(\sqrt{5}-2\)
\(\left(x-1\right)\left(x+1\right)\left(x+3\right)\left(x+5\right)\)\(=-16\)
\(\Leftrightarrow\left(x-1\right)\left(x+5\right)\left(x+1\right)\left(x+3\right)\)\(=-16\)
\(\Leftrightarrow\left(x^2+4x-5\right)\left(x^2+4x+3\right)\)\(=-16\)
đặt \(x^2+4x-1=t\)
\(\Rightarrow\left(t-4\right)\left(t+4\right)=-16\)
\(\Leftrightarrow t^2-16=-16\)
\(\Leftrightarrow t^2=0\Leftrightarrow t=0\)
\(\Leftrightarrow x^2+4x-1=0\)
\(\Leftrightarrow x^2+4x+4-5=0\)
\(\Leftrightarrow\left(x+2\right)^2-5=0\)
\(\Leftrightarrow\left(x+2\right)^2-\sqrt{5}^2=0\)
\(\Leftrightarrow\left(x+2-\sqrt{5}\right)\left(x+2+\sqrt{5}\right)=0\)
\(\Rightarrow x=-2-\sqrt{5};-2+\sqrt{5}\)
vậy.........