5.( 7 - 3x ) + 14 = -14.x
Giải các phương trình sau:
a) − 3 x = 4 ; b) 3 + x 2 + 1 = 5 ;
c) x − 1 4 − 7 = 5 − x − 1 4 d) 1 − 8 x + 4 5 = 2 .
\(\dfrac{3x-5}{x+7}-\dfrac{3x-3}{x+2}>\)\(\dfrac{3}{x^2+9x+14}\)
Tính.
a, (x3-2x2-10x-7):(x2-7-3x)
b, (x3+4x2+8x+5):(x+1)
c, (x3-x2-13x-14):(x2-3x-7)
d, (x3+5x2+5x):(x+5)
a: \(=\dfrac{x^3-3x^2-7x+x^2-3x-7}{x^2-3x-7}=x+1\)
b:\(=\dfrac{x^3+x^2+3x^2+3x+5x+5}{x+1}=x^2+3x+5\)
c:\(=\dfrac{x^3-3x^2-7x+2x^2-6x-14}{x^2-3x-7}=x+2\)
d: \(=\dfrac{x^2\left(x+5\right)+5x+25-25}{x+5}=x^2+5-\dfrac{25}{x+5}\)
tìm x biết
a, (3x - 5)(2x + 3) - 6x2 = 7
b, x(x - 7 ) - 2x + 14 = 0
a,2.(x-5)-3.(x+7)=14
b,5.(x-6)-2.(x+3)=12
c,-5.(2-x)+4.(x-3)=10.x-15
d,-7.(3x-5)+2.(7.x-14)=28
e,5.(4-x)-7.(-x+2)=4-9+3
f,-4.(2.x+1)+8.(3-2.x)=24
1.Giai pt bang cach dat an phu :
a, 3x + 14 + 5\(\sqrt{x-2}\) = 7(\(\sqrt{x+1}+\sqrt{x^2-x-2}\) )
b, 7\(\sqrt{3x-7}\) +(4x-7)\(\sqrt{7-x}\) =32
Bài 1:
a)x/0,9=5/6
b)-6/x=9/-15
c)14/15:9/10=x:3/7
d)1/3/5 :8=2,5:x
e)3x-7=5/2
f)x:0,2=0,8:x
g)x+11/14-x=2/3
(1/3/5 là 1 và 3/5 nhé)
a: \(\dfrac{x}{0.9}=\dfrac{5}{6}\)
\(\Leftrightarrow x=\dfrac{3}{4}\)
b: \(\dfrac{-6}{x}=\dfrac{9}{-15}\)
\(\Leftrightarrow x=10\)
c: \(\dfrac{\dfrac{14}{15}}{\dfrac{9}{10}}=\dfrac{x}{\dfrac{3}{7}}\)
\(\Leftrightarrow x=\dfrac{3}{7}\cdot\dfrac{14}{15}:\dfrac{9}{10}=\dfrac{2}{5}\cdot\dfrac{10}{9}=\dfrac{20}{45}=\dfrac{4}{9}\)
1. Cho x=\(\sqrt[3]{7+5\sqrt{2}}-\frac{1}{\sqrt[3]{7-5\sqrt{2}}}\)
Chứng minh rằng: \(^{x^3+3x-14=0}\)
2. Cho x=\(\sqrt[3]{20+14\sqrt{2}}+\sqrt[3]{20-14\sqrt{2}}\)
Tính: A=\(\left(x^3-3x^2+x-19\right)^{2019}\)
Tìm x thuộc Z biết:
a) 4(x+1) - (3x+1)=14
b) -12(x-5) + 7(3x) =5
c) 17(x+2) - 4(x-7) - 9x = 82
a) 4(x+1)-(3x+1)=14
<=>4x+4-3x-1=14
<=>4x-3x = 14-4
<=>x=10
b) -12(x-5) +7.(3x)=5
<=> -12x +60 + 21+7x=5
<=> -12x+7x=5-60-21
<=> -5x=-76
<=> x=76/5
c) 17x + 34 -4x+28-9x=82
<=> 17x-9x-4x=82-34-28
<=> 4x=20
<=> x=5