tim x thuoc Z
(10-x)+48=40-(2-x)
Tim x thuoc Z: (x+1)+(x+2)+(x+3)+...+(x+40)=1000
\(\left(x+1\right)+\left(x+2\right)+...+\left(x+40\right)=1000\)
\(x+1+x+2+...+x+40=1000\)
\(40x+\left(1+2+3+...+40\right)=1000\)
số số hạng của dãy 1+2+3+...+40 là
\(\left(40-1\right):1+1=40\)
tổng dãy trên là
\(\left(40+1\right).40:2=820\)
thay vào
\(40x+820=1000\)
\(40x=1000-820\)
\(40x=180\)
\(\Rightarrow x=180:40=4,5\)
\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+....+\left(x+40\right)=1000\)
Từ 1 đến 40 có 40 số số hạng => Có 40 x
\(\Leftrightarrow\left(x+x+x+....+x\right)+\left(1+2+3+....+40\right)=1000\)
\(\Leftrightarrow40x+\frac{\left(40+1\right)\cdot40}{2}=1000\)
\(\Leftrightarrow40x+820=1000\)
\(\Leftrightarrow40x=180\)
\(\Leftrightarrow x=\frac{18}{4}=\frac{9}{2}\)
TIm x thuoc Z
38 + 48 : x =32 . 6
=> 38 + 48 : x = 54
=> 48 : x = 54 - 38 = 16
=> x = 48 : 16 = 3
Vậy x=3
k mk nha
38 + 48 : x = 32 . 6
38 + 48 : x = 9 . 6
38 + 48 : x = 36
48 : x = 36 - 38
48 : x = -2
x = 48 : ( -2 )
x = -24
38+48:x=9.6
38+48:x=54
48:x = 54-38
48:x= 16
x= 48:16
x=3
Tim x, y thuoc Z biet : | x + 45 - 40 | + | y + 10 - 11 | nho hon hoac bang 0
tim x thuoc z biet /x+1/ +/x-2/+/x+7/=5x-10
1 )Tim x, y thuoc Z
x + y = x.y
2) Tim x thuoc Z
(x + 1)+(x+3)+(x+5)+...+(x+99)=0(x-3)+(x-2)+(x-1)+...+10+11=11-12(x-5)+7(3-x)=530(x+2)-6(x-5)-24x=100x + y = x.y
=> xy - x - y = 0
=> (xy - x) - y + 1 = 1
=> x(y - 1) - (y - 1) = 1
=> (x - 1)(y - 1) = 1
=> x - 1 = y - 1 = 1 hoặc x - 1 = y - 1 = -1
=> x = y = 2 hoặc x = y = 0
Tim x thuoc Z
(x-3)+(x-2)+(x-1)+...+10+11=11
tim x thuoc Z thoa man : (x^2 - 20)(x^2-15)(x^2 - 10)(x^2 - 5 )<0
https://www.youtube.com/channel/UCjP80p-OtLhNnRs-R4Q7yjw
tim x thuoc z biet /x+1/ +/x-2/+/x+7/=5x-10
CHO E=\(\left(\frac{x^3}{x^3-4x}+\frac{6}{6-3x}+\frac{1}{2+x}\right):\left(x+2+\frac{10-x^2}{x-2}\right)\)
a) Rut gon E
b) Tim x thuoc Z sao cho E thuoc Z