Tim x biet: (\(2x^2+7\))x(\(-3x-9\))<\(0\)
Giup mik voi ai nhanh mik tik cho^-^
Nho lam day du ho mik nhe,Thanks=))
Tim xthuoc Z biet:
1,|2x-5|-|2x+9|=0
2,|x+1|-|x+2|-|3-x|=7
3,|2x+3|+|3x+2|-|4-x|=10
tim x biet
(2x=1)^2 - 4(x=2)^2=9
3(x-1)^2 -3x(x-5)=1
3(x+2)^2+ (2x-1)^2 =7
7(x+3)(x-3)=36
tim x biet (x^2+2x+1)(x+2)-x^2(x-3)-7x(x-1)=3x-9
tim x biet;6x^2-(2x+5)(3x-2)=7
\(6x^2-\left(2x+5\right)\left(3x-2\right)=7.\)
\(6x^2-\left(6x^2-4x+15x-10\right)=7\)
\(6x^2-6x^2+4x-15x+10=7\)
\(-11x+10=7\)
\(-11x=-3\)
\(x=\frac{-3}{-11}=\frac{3}{11}\)
\(6x^2-\left(2x+5\right)\left(3x-2\right)=7\)
\(6x^2-\left(6x^2-4x+15x-10\right)=7\)
+ Áp dụng quy tắc bở ngoặc ta có :
\(6x^2-6x^2+4x-15x+10=7\)
\(-11x+10=7\)
\(-11x=7-10\)
\(-11x=-3\)
\(x=-3:-11\)
\(x=\frac{-3}{-11}\)
\(\Rightarrow x=\frac{3}{11}\)
Vậy \(x=\frac{3}{11}\)
Chúc bạn học tốt !!!
ai giup minh vs
tim x biet
(3x+2)(2x+9)-(x+2)(6x+1)=x+1-(x-9)
\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=x+1-\left(x-9\right)\)
\(\Rightarrow6x^2+27x+4x+18-6x^2-x-12x-2=10\)
\(\Rightarrow18x+16=10\)
\(\Rightarrow18x=-6\)
\(\Rightarrow x=-\frac{6}{18}=-\frac{1}{3}\)
tim x biet /3x+4/=2/2x-7/
tim x biet 2x+9/x+2 + 5x+17/ x+3 - 3x/ x+3 ( x thuoc Z)
bai 1)tim x biet
a )24-(36+5)=x
b)14-21=(13-x)-(15+8)
bai 2) tim x biet
a)17-x=-25+(-16+9)
b)3x-21=-19-(-2x)
Bài 1: Tìm x, biết
a )24-(36+5)=x b)14-21=(13-x)-(15+8)
24-41=x (13-x)-23=-7
x=-17 13-x=(-7)+23
Vậy x=-17 13-x=16
x=13-16
x=-3 Vậy x=-3
Bài 2:Tìm x, biết
a)17-x=-25+(-16+9) b)3x-21=-19-(-2x)
17-x=-25+(-7) 3x-21=-19+2x
17-x=-32 3x-2x=-19+21
x=17-(-32) x=4
x=49 Vậy x=4
Vậy x=49
Bài 1:
a. 24 - (36+5) = x
=> 24 - 41 = x
=> -17 = x
=> x = -17
b. 14 - 21 = (13 - x) - (15 + 8)
=> -7 = 13 - x - 23
=> -7 - 13 + 23 = -x
=> 3 = -x
=> x = -3
Bài 2:
a. 17 - x = -25 + (-16 + 9)
=> 17 - x = -25 + (-7)
=> 17 - x = -32
=> 17 + 32 = x
=> x = 49
b. 3x - 21 = -19 - (-2x)
=> 3x - 21 = -19 + 2x
=> 3x - 2x = -19 + 21
=> x = 2
Bài1
a)24-(36+5)=x\(\Rightarrow\)x=24-41=-17
b)14-21=(13-x)-(15+8)\(\Rightarrow\)(13-x)-(15+8)=-7\(\Rightarrow\)13-x=-7+23=16\(\Rightarrow\)x=13-16=-3
Bài2
a)17-x=-25+(-16+9)\(\Rightarrow\)17-x=-25+-7\(\Rightarrow\)17-x=-32\(\Rightarrow\)x=17-(-32)=17+32=49
b)3x-21=-19-(-2x)\(\Rightarrow\)3x-(-2x)=-19-21\(\Rightarrow\)3x+2x=-40\(\Rightarrow\)5x=-40\(\Rightarrow\)x=-8
Tim x biet:
a.|x|+|x+2|=3
b.|3x-5|=|x+2|
c.|2x+3|-4x<9
c) |2x + 3| - 4x < 9
Xét x ≥ -3/2
=> |2x + 3| - 4x < 9
<=> 2x + 3 - 4x < 9
<=> - 2x + 3 < 9
=> - 2x < 6
=> x < - 3
Xét x < -3/2 tương tự
b,xet 2 TH
TH1 3x-5=x+2
=>3x-x=2+5
=>2x=7
=>x=7/2
TH2 5-3x=x+2
=>-3x-x=5-2
=>-2x=3
=>x=-3/2
THẤY ĐÚNG THÌ
THANK
bạn dinhkhachoang lam sai r . TH2 phải là -3x-x=-4x , k0 phải là -2
tim x biet
45-(3x+9)/13=42
(x+1)+(2x+2)+.....+(20x+20)=1050
a) \(\frac{45-\left(3x+9\right)}{13}=42\)
\(\Leftrightarrow45-\left(3x+9\right)=546\)
\(\Leftrightarrow3x+9=-501\)
\(\Leftrightarrow3x=-510\)
\(\Leftrightarrow x=-170\)
b) \(\left(x+1\right)+\left(2x+2\right)+...+\left(20x+20\right)=1050\)
\(\Leftrightarrow x+1+2x+2+...+20x+20=1050\)
\(\Leftrightarrow\left(x+1\right)+2\left(x+1\right)+....+20\left(x+1\right)=1050\)
\(\Leftrightarrow\left(x+1\right)\left(1+2+3+...+20\right)=1050\)
\(\Leftrightarrow\left(x+1\right)\left[\frac{\left(20+1\right).20}{2}\right]=1050\)
\(\Leftrightarrow\left(x+1\right).210=1050\)
\(\Leftrightarrow x+1=5\)
\(\Leftrightarrow x=4\)