(5X)^3-1
3/5x-1+3/3-5x=4/(1-5x)(5x-3)
\(\dfrac{3}{{5x - 1}} + \dfrac{2}{{3 - 5x}} = \dfrac{4}{{\left( {1 - 5x} \right)\left( {x - 3} \right)}}\)
ĐKXĐ: \(x \ne \dfrac{1}{5};x\ne \dfrac{3}{5};x \ne 3\)
\( \Leftrightarrow 3\left( {3 - 5x} \right)\left( {x - 3} \right) + 2\left( {5x - 1} \right)\left( {x - 3} \right) + 4\left( {3 - 5x} \right) = 0\\ \Leftrightarrow 9x - 27 - 15{x^2} + 45x + 10{x^2} - 30x - 2x + 6 + 12 - 20x = 0\\ \Leftrightarrow - 5{x^2} + 2x - 9 = 0 \)
\(\Rightarrow\) Phương trình vô nghiệm.
8x-1/5x-1 + 7x-3/3-5x = 4/(1-5x)(5x-3)
a. P=(5x−1)2+2(1−5x)(4+5x)+(5x+4)2P=(5x−1)2+2(1−5x)(4+5x)+(5x+4)2
b. Q=(x−y)3+(y+x)3+(y−x)3−3xy(x+y)
Bài 1: Giải các phương trình: a)(5x^ 2 -45).( 4x-1 5 - 2x+1 3 )=0 b) (x^ 2 -2x+6).(2x-3)=4x^ 2 -9 d) 3 5x-1 + 2 3-5x = 4 (1-5x).(5x-3) c) (2x + 19)/(5x ^ 2 - 5) - 17/(x ^ 2 - 1) = 3/(1 - x) e) 3/(2x + 1) = 6/(2x + 3) + 8/(4x ^ 2 + 8x + 3) (x^ 2 -3x+2).(x^ 2 -9x+20)=40 (2x + 5)/95 + (2x + 6)/94 + (2x + 7)/93 = (2x + 93)/7 + (2x + 94)/6 + (2x + 95)/5 Bài 2: Giải các phương trình sau: g) a) (x + 2) ^ 2 + |5 - 2x| = x(x + 5) + 5 - 2x b) (x - 1) ^ 2 + |x + 21| - x ^ 2 - 13 = 0 d) |3x + 2| + |1 - 2x| = 5 - |x| c) |5 - 2x| = |1 - x| Bài 3: Cho biểu thức A = ((x + 2)/(x + 3) - 5/(x ^ 2 + x - 6) + 1/(2 - x)) / ((x ^ 2 - 5x + 4)/(x ^ 2 - 4)) a) Rút gọn A. b) Tim x de A = 3/2 c) Tìm giá trị nguyên c dot u a* d hat e A có giá trị nguyên. B = ((2x)/(2x ^ 2 - 5x + 3) - 5/(2x - 3)) / (3 + 2/(1 - x)) Bài 4: Cho biểu thức a) Rút gọn B. b) Tim* d tilde e B>0 . c) Tim* d hat e B= 1 6-x^ 2 . Bài 5: Cho biểu thức H = (2/(1 + 2x) + (4x ^ 2)/(4x ^ 2 - 1) - 1/(1 - 2x)) / (1/(2x - 1) - 1/(2x + 1)) a) Rút gọn H. b) Tìm giá trị nhỏ nhất của H. c)Tim* d vec e bi vec e u thic H= 3 2
5x+5x+1+5x+2+5x+3=1+2+3+...+87+88-42
\(5^x+5^{x+1}+5^{x+2}+5^{x+3}=1+2+3+...+87+88-4^2\)
=>\(5^x+5^x\cdot5+5^x\cdot25+5^x\cdot125=88\cdot\dfrac{\left(88+1\right)}{2}-16\)
=>\(156\cdot5^x=44\cdot89-16=3900\)
=>\(5^x=\dfrac{3900}{156}=25\)
=>x=2
5x+5x+1+5x+2+5x+3=1+2+3+...+87+88-42
giúp mình với
Lời giải:
$5^x+5^{x+1}+5^{x+2}+5^{x+3}=1+2+3+...+87+88-4^2$
$5^x(1+5+5^2+5^3)=88.89:2-16$
$5^x.156=3900$
$5^x=3900:156=25=5^2$
$\Rightarrow x=2$
Thực hiện phép tính
a, (2x^3-4x+5x):(-3/2x)
b, (4x^3-5x+x):(2x-1)
c, (-3x^4+5x^3+6x^2-7x+1):(x^2+3x-1)
đ, (3^3-5x+2):(x-3)
a: \(=2x^3:\dfrac{-3}{2}x+4x:\dfrac{3}{2}x-5:\dfrac{3}{2}\)
=-4/3x^2+8/3-10/3
=-4/3x^2-2/3
d: \(\dfrac{3x^3-5x+2}{x-3}=\dfrac{3x^3-9x^2+9x^2-27x+22x-66+68}{x-3}\)
\(=3x^2+9x+22+\dfrac{68}{x-3}\)
\(\frac{3}{5x-1}+\frac{2}{3-5x}=\frac{4}{\left(5x-1\right)\left(3-5x\right)}\)
\(\frac{3}{\left(5x-1\right)}+\frac{2}{3-5x}=\frac{4}{\left(5x-1\right)\left(3-5x\right)}\)
\(\Rightarrow9-15x+10x-2=4\)
\(\Leftrightarrow3-5x=0\)
\(\Leftrightarrow x=\frac{3}{5}\)
\(\frac{3}{\left(5x-1\right)}+\frac{2}{3-5x}=\frac{4}{\left(5x-1\right)\left(3-5x\right)}\)
⇒9 − 15x + 10x − 2 = 4
⇔3 − 5x = 0
⇔x =\(\frac{3}{5}\)
\(\frac{3}{5x-1}-\frac{2}{3-5x}=\frac{4}{\left(1-5x\right)\left(5x-3\right)}\)
\(ĐKXĐ:x\ne\frac{1}{5},x\ne\frac{3}{5}\)
Ta có : \(\frac{3}{5x-1}=\frac{2}{3-5x}=\frac{4}{\left(1-5x\right)\left(5x-3\right)}\)
\(\Leftrightarrow\frac{3\left(3-5x\right)}{\left(5x-1\right)\left(3-5x\right)}-\frac{2\left(5x-1\right)}{\left(5x-1\right)\left(3-5x\right)}+\frac{4}{\left(5x-1\right)\left(5x-3\right)}=0\)
\(\Rightarrow9-15x-10x+2+4=0\)
\(\Leftrightarrow-25x=-15\)
\(\Leftrightarrow x=\frac{3}{5}\) ( không thỏa mãn \(ĐKXĐ\) )
Vậy pt đã cho vô nghiệm
(5x+1)-(5x-3)(5x+3)=30
Hình như bạn ghi sai đề. Đề đúng: \(\left(5x+1\right)^2-\left(5x-3\right)\left(5x+3\right)=30\)
\(\left(5x+1\right)^2-\left(5x-3\right)\left(5x+3\right)=30\)
\(\Leftrightarrow25x^2+10x+1-25x^2+9=30\)
\(\Leftrightarrow10x+10=30\)
\(\Leftrightarrow10x=20\)
\(\Leftrightarrow x=2\)