BÀI 1: Giải phương trình sau:
a. (x - 4)3 = (x + 4)(x2 - x - 16)
b. \(\dfrac{x+2}{x}=\dfrac{x^2+5x+4}{x^2+2x}+\dfrac{x}{x+2}\)
c. \(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^2-4}+1\)
d. (x + 3)2 - 25 = 0
e. \(\dfrac{3}{2x+10}+\dfrac{2x}{25-x^2}+\dfrac{3}{x-5}=0\)
f. \(\dfrac{x+5}{x-1}-\dfrac{x-1}{x-3}=\dfrac{8}{x^2-4x-3}\)
BÀI 2: Tìm m để phương trình sau số nghiệm x = 1:
3.(2x + m)(x + 2) - 2.(2x+1) = 18
BÀI 3: Giải phương trình:
a. (x-2)2 - 4.(x + 3) = x.(x-4)
b....
Đọc tiếp
BÀI 1: Giải phương trình sau:
a. (x - 4)3 = (x + 4)(x2 - x - 16)
b. \(\dfrac{x+2}{x}=\dfrac{x^2+5x+4}{x^2+2x}+\dfrac{x}{x+2}\)
c. \(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^2-4}+1\)
d. (x + 3)2 - 25 = 0
e. \(\dfrac{3}{2x+10}+\dfrac{2x}{25-x^2}+\dfrac{3}{x-5}=0\)
f. \(\dfrac{x+5}{x-1}-\dfrac{x-1}{x-3}=\dfrac{8}{x^2-4x-3}\)
BÀI 2: Tìm m để phương trình sau số nghiệm x = 1:
3.(2x + m)(x + 2) - 2.(2x+1) = 18
BÀI 3: Giải phương trình:
a. (x-2)2 - 4.(x + 3) = x.(x-4)
b. \(\dfrac{3}{x+1}+\dfrac{x-1}{x-2}=\dfrac{x}{x-2}\)
c. \(\dfrac{x}{2x-6}+\dfrac{x}{2x+2}=\dfrac{2x^2}{x^2-2x-3}\)
d. (x + 3)2 - (x - 3)2 = 6x + 18
e. \(\dfrac{x+3}{x-2}=\dfrac{5}{\left(x-2\right)\left(3-x\right)}\)
f. \(\dfrac{12x^2+30x-21}{16x^2-9}-\dfrac{3x-7}{3-4x}=\dfrac{6x+5}{4x+3}\)
g. \(\dfrac{4}{x+1}-\dfrac{2}{x-2}=\dfrac{x+3}{x^2-x-2}\)
GIÚP MÌNH VỚI NHA !!!!
a.
| x | = 5,6
=>\(\left[{}\begin{matrix}x=5,6\\x=-5,6\end{matrix}\right.\)
Vậy \(x\in\left\{-5,6;5,6\right\}\)
b, \(\left|x-3,5\right|=5\)
=>\(\left[{}\begin{matrix}x-3,5=5\\x-3,5=-5\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=8,5\\x=-1,5\end{matrix}\right.\)
Vậy \(x\in\left\{-1,5;8,5\right\}\)
c,\(\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0\)
=> \(\left|x-\dfrac{3}{4}\right|=\dfrac{1}{2}\)
=>\(\left[{}\begin{matrix}x-\dfrac{3}{4}=\dfrac{1}{2}\\x-\dfrac{3}{4}=-\dfrac{1}{2}\end{matrix}\right.\)
=> \(\left[{}\begin{matrix}x=\dfrac{5}{4}\\x=\dfrac{1}{4}\end{matrix}\right.\)
Vậy \(x\in\left\{\dfrac{1}{4};\dfrac{5}{4}\right\}\)
d,\(\left|4x\right|-\left(\left|-13,5\right|\right)=\left|\dfrac{1}{4}\right|\)
=> \(\left|4x\right|-13,5=\dfrac{1}{4}\)
=> \(\left|4x\right|=13,75\)
=>\(\left[{}\begin{matrix}4x=13,75\\4x=-13,75\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=3,4375\\x=-3,4375\end{matrix}\right.\)
Vậy \(x\in\left\{-3,4375;3,4375\right\}\)
e, ( x - 1 ) 3 = 27
=> x - 1 = 3
=> x = 4
Vậy x = 4
f, ( 2x - 3)2 = 36
=> \(\left[{}\begin{matrix}2x-3=6\\2x-3=-6\end{matrix}\right.\)
=> \(\left[{}\begin{matrix}x=4,5\\x=-1,5\end{matrix}\right.\)
Vậy x\(\in\left\{-1,5;4,5\right\}\)
g, \(5^{x+2}=625\)
=> \(5^{x+2}=5^4\)
=> x + 2 = 4
=> x = 2
Vậy x = 2
h, ( 2x - 1)3 = -8
=> 2x - 1 = -2
=> x = \(\dfrac{-1}{2}\)
Vậy x = \(\dfrac{-1}{2}\)
i, \(\dfrac{1}{4}.\dfrac{2}{6}.\dfrac{3}{8}.\dfrac{4}{10}.\dfrac{5}{12}...\dfrac{30}{62}.\dfrac{31}{64}=2^x\)
=> \(\dfrac{1.2.3.4.5...30.31}{4.6.8.10.12...62.64}=2^x\)
=>\(\dfrac{1.2.3.4.5...30.31}{\left(2.3.4.5...30.31.32\right)\left(2.2.2.2...2.2_{ }\right)}=2^x\)(có 31 số 2)
=> \(\dfrac{1}{32.2^{31}}=2^x\)
=> \(\dfrac{1}{2^{36}}=2^x\)
=> x = -36
Vậy x = -36