Tim x thuoc z de bieu thuc sau co gia tri nguyen:M=x+2/3
Những câu hỏi liên quan
cho bieu thuc: M=x^2-5 phan x^2 (x thuoc Z)
Tim x thuoc Z de M co gia tri nguyen
choo bieu thuc
A=2x+1/x-3
a, tinh gia tri cua A khi x2=4
b, tim x de A=1/3
c, tim x thuoc z de A co gia tri nguyen
Tim x thuoc Z de bieu thuc sau day dat gia tri lon nhat :
B= 2015x+1/2016x-2016 (x thuoc Z; x khac 1)
tim x thuoc N de bieu thuc sau co gia tri la so tu nhien: Q=\(\dfrac{\text{x}+1}{\text{x}-\sqrt{\text{x}}+1}\)
Ta có :
\(Q=\dfrac{x+1}{x-\sqrt[]{x}+1}\left(x\inℕ\right)\)
\(\Leftrightarrow Q=\dfrac{\left(x+1\right)\left(\sqrt[3]{x}+1\right)}{\left(\sqrt[3]{x}+1\right)\left(x-\sqrt[]{x}+1\right)}\)
\(\Leftrightarrow Q=\dfrac{\left(x+1\right)\left(\sqrt[3]{x}+1\right)}{\left(x+1\right)}\)
\(\Leftrightarrow Q=\sqrt[3]{x}+1\)
Để \(Q\inℕ\)
\(\Leftrightarrow\sqrt[3]{x}+1\inℕ\)
\(\Leftrightarrow\sqrt[3]{x}\inℕ\)
\(\Leftrightarrow x=\left\{x\inℕ|x=k^3;k\inℕ\right\}\)
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tim gia tri x nguyen de bieu thuc (3x2-4x+x-1)/(3x+2) co gia tri nguyen
tim gia tri x nguyen de bieu thuc (3x3-4x2+x+1)/(x-4) co gia tri nguyen
Cho bieu thuc: ( x-1/ x+1 - x-1/x+1) : 2x / 3x - 3
a, Tim dieu kien xac dinh cua bieu thuc P
b, Rut gon bieu thuc P
c, Tim x thuoc z de P nhan gia tri nguyen.
Đề bài sai rồi bạn ! Mình sửa :
a) \(ĐKXĐ:\hept{\begin{cases}x\ne0\\x\ne\pm1\end{cases}}\)
b) \(P=\left(\frac{x-1}{x+1}-\frac{x+1}{x-1}\right):\frac{2x}{3x-3}\)
\(\Leftrightarrow P=\frac{\left(x-1\right)^2-\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}\cdot\frac{3\left(x-1\right)}{2x}\)
\(\Leftrightarrow P=\frac{x^2-2x+1-x^2-2x-1}{\left(x-1\right)\left(x+1\right)}\cdot\frac{3\left(x-1\right)}{2x}\)
\(\Leftrightarrow P=\frac{-4x}{\left(x-1\right)\left(x+1\right)}\cdot\frac{3\left(x-1\right)}{2x}\)
\(\Leftrightarrow P=\frac{-6}{x+1}\)
c) Để P nhận giá trị nguyên
\(\Leftrightarrow\frac{-6}{x+1}\inℤ\)
\(\Leftrightarrow x+1\inƯ\left(6\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\)
\(\Leftrightarrow x\in\left\{-2;0;-3;1;-4;2;-7;5\right\}\)
Ta loại các giá trị ktm
\(\Leftrightarrow x\in\left\{-2;-3;-4;2;-7;5\right\}\)
Vậy để \(P\inℤ\Leftrightarrow x\in\left\{-2;-3;-4;2;-7;5\right\}\)
bai 1
cho bieu thuc A = 5/n+1 voi N THUOC Z
a, de A la phan so thi n co dieu kien gi ?
b , tim tat ca cac gia tri nguyen cua n de gia tri A la 1 so nguyen ?
bai 2
cho bieu thuc M = 6/n-3 voi n thuoc Z .Co bao nhieu gia tri cua n de :
a, M ko phai la phan so
b , M la phan so va cp gia tri nguyen ?
bai 3 viet tap hop cacs so nguyen sao cho :
-12/4 < x <6/3
Bài 1:
a: Để A là phân số thì n+1<>0
hay n<>-1
b: Để A là số nguyên thì \(n+1\in\left\{1;-1;5;-5\right\}\)
hay \(n\in\left\{0;-2;4;-6\right\}\)
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Thu gon bieu thuc sau roi tim gia tri cua x de bieu thuc co gia tri la so am
7 × -19 × x + 6 × x
Tim x de bieu thuc sau co gia tri duong : (x-3)×(x7)