cho \(A=\frac{4x}{x+2}+\frac{2}{x-2}+\frac{5x-6}{4-x^2}\)
voi \(x\ne\pm2\)
a) rut gon A
b)tim x de \(A-\frac{1}{x}=-1\)
Những câu hỏi liên quan
cho biểu thức A left(frac{3}{4}+frac{3}{x^2+3x}right)chialeft(frac{x^2}{27-3x}+frac{1}{x+3}right)a, rut gon A b, tim x de a-1c, tim cac gia tri nguyen cua x de A co gia tri nguyencho bthuc B left(frac{x^2}{x^3-4x}+frac{6}{6-3x}+frac{1}{x-2}right)chialeft(x-2+frac{16-x^2}{x+2}right)rut gon B tính b khi /x/ 1/2tim x de b2tim x in z de b in z
Đọc tiếp
cho biểu thức A= \(\left(\frac{3}{4}+\frac{3}{x^2+3x}\right)chia\left(\frac{x^2}{27-3x}+\frac{1}{x+3}\right)\)
a, rut gon A
b, tim x de a<-1
c, tim cac gia tri nguyen cua x de A co gia tri nguyen
cho bthuc B = \(\left(\frac{x^2}{x^3-4x}+\frac{6}{6-3x}+\frac{1}{x-2}\right)chia\left(x-2+\frac{16-x^2}{x+2}\right)\)rut gon B tính b khi /x/ = 1/2tim x de b=2tim x \(\in\) z de b \(\in\) z
Bài 2:
a: \(B=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{6}{3\left(x-2\right)}+\dfrac{1}{x-2}\right):\left(\dfrac{x^2-4+16-x^2}{x+2}\right)\)
\(=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{2}{x-2}+\dfrac{1}{x-2}\right):\dfrac{12}{x+2}\)
\(=\left(\dfrac{x}{\left(x-2\right)\left(x+2\right)}-\dfrac{1}{x-2}\right):\dfrac{12}{x+2}\)
\(=\dfrac{x-x-2}{\left(x-2\right)\left(x+2\right)}\cdot\dfrac{x+2}{12}=\dfrac{-1}{6\left(x-2\right)}\)
b: Thay x=1/2 vào B, ta được:
\(B=\dfrac{-1}{6\cdot\left(\dfrac{1}{2}-2\right)}=\dfrac{-1}{6\cdot\dfrac{-3}{2}}=\dfrac{1}{9}\)
Thay x=-1/2 vào B, ta được:
\(B=\dfrac{-1}{6\cdot\left(-\dfrac{1}{2}-2\right)}=-\dfrac{1}{15}\)
c: Để B=2 thì \(\dfrac{-1}{6\left(x-2\right)}=2\)
=>6(x-2)=-1/2
=>x-2=-1/12
hay x=23/12
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Cho bieu thuc:
\(P=\frac{x+2}{x+3}-\frac{5}{x^2+x+6}+\frac{1}{2-x}\)voi \(x\ne-3;x\ne2\)
a, Rut gon P
b, tim x de \(P=\frac{-3}{4}\)
c,tim x nguyen de P dat gia tri nguyen
(mk dang can gap ai giai dung dau tien mk tick cho)
\(A=\frac{\sqrt{x}+4}{\sqrt{x}+2};B=\left(\frac{\sqrt{x}}{\sqrt{x}+4}+\frac{4}{\sqrt{x}-4}\right):\frac{x+16}{\sqrt{x}+2}\)
a. rut gon B
b. Tim x nguyen de P = B(A-1) nguyen
giup minh voi a
Cho A = \(\frac{3\sqrt{x}-3}{x\sqrt{x}-2x+2\sqrt{x}-1}-\frac{4x\sqrt{x}-4}{x^3-1}\)(x>1). Rut gon A va tim x de A=1
cho A=\(\left(\frac{x^2}{x^3-4x}+\frac{6}{6-3x}+\frac{1}{x+2}\right)\)\(\div\)\(\left(x-2+\frac{10-x^2}{x+2}\right)\)
a, Rut gon A
b, Tim x de A=2
Cho bthuc: \(A=\frac{1}{2\sqrt{x}-2}-\frac{1}{2\sqrt{x}+2}+\frac{\sqrt{x}}{1-x}\)
a) Rut gon A
b) Tim gia tri cua x de /A/ =\(\frac{1}{2}\)
c) Tim x nguyen de A co gia tri nguyen
Qfrac{x+2}{x+3}-frac{5}{x^2+x-6}+frac{1}{2-x} a)rut gon b)tim x de Qfrac{-3}{4}
Đọc tiếp
Q=\(\frac{x+2}{x+3}\)-\(\frac{5}{x^2+x-6}\)+\(\frac{1}{2-x}\) a)rut gon b)tim x de Q=\(\frac{-3}{4}\)
\(Q=\frac{x+2}{x+3}-\frac{5}{x^2+x-6}+\frac{1}{2-x}\)
\(\Leftrightarrow\) \(Q=\frac{\left(x-2\right)\left(x+2\right)}{\left(x+3\right)\left(2-x\right)}+\frac{5}{\left(x+3\right)\left(2-x\right)}+\frac{-1}{\left(x+3\right)\left(2-x\right)}\)
\(\Rightarrow\) \(Q=\left(x-2\right)\left(x+2\right)+5-1\)
\(\Leftrightarrow\) \(Q=x^2-4+5-1\)
\(\Leftrightarrow\) \(Q=x^2\)
Thay \(Q=\frac{-3}{4}\) ta được:
\(x^2=\frac{-3}{4}\)
Vì \(\frac{-3}{4}>0\forall x\)
\(\Rightarrow\) Pt vô nghiệm
Vậy không có giả trị nào của x thỏa mãn \(Q=\frac{-3}{4}\)
Chúc bn học tốt!!
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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
cho bieu thuc:
\(A=\left(\frac{2+x}{2-x}-\frac{4x^2}{x^2-4}-\frac{2-x}{2+x}\right):\left(\frac{x^2-3x}{2x^2-x^3}\right)\)
a. Tim DKXD roi rut gon A
b. Tim x de A>0
c. Tinh gia tri cua A khi \(\left|x-7\right|=4\)