Tìm x,biết:
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}=0\)
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}+4=0\)
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}+4=0\\ \Leftrightarrow\dfrac{315-x}{101}+1+\dfrac{313-x}{103}+1+\dfrac{311-x}{105}+1+\dfrac{309-x}{107}+1=0\\ \Leftrightarrow\dfrac{416-x}{101}+\dfrac{416-x}{103}+\dfrac{416-x}{105}+\dfrac{416-x}{107}=0\\ \Leftrightarrow\left(416-x\right)\left(\dfrac{1}{101}+\dfrac{1}{103}+\dfrac{1}{105}+\dfrac{1}{107}\right)=0\\ \dfrac{1}{101}+\dfrac{1}{103}+\dfrac{1}{105}+\dfrac{1}{107}>0\\ \Rightarrow416-x=0\\ \Leftrightarrow x=416\)
Tìm x, biết
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}=4\)
Lời giải:
\(\frac{315-x}{101}+\frac{313-x}{103}+\frac{311-x}{105}+\frac{309-x}{107}=4\)
\(\Leftrightarrow \frac{315-x}{101}-1+\frac{313-x}{103}-1+\frac{311-x}{105}-1+\frac{309-x}{107}-1=0\)
\(\Leftrightarrow \frac{416-x}{101}+\frac{416-x}{103}+\frac{416-x}{105}+\frac{416-x}{107}=0\)
\(\Leftrightarrow (416-x)\left(\frac{1}{101}+\frac{1}{103}+\frac{1}{105}+\frac{1}{107}\right)=0\)
Vì \(\frac{1}{101}+\frac{1}{103}+\frac{1}{105}+\frac{1}{107}\neq 0\) nên suy ra $416-x=0$
\(\Rightarrow x=416\)
a) Tìm x biết
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}+4=0\)
b) Cho a,b,c là các số thực khác 0 thỏa mãn
\(\dfrac{a-b+c}{b}=\dfrac{a+b-c}{c}=\dfrac{-a+b+c}{a}\)
Tính giá trị của biểu thức :
P=\(\dfrac{\left(a+b\right)\left(b+c\right)\left(c+a\right)}{abc}\)
Tìm x biết:
\(\dfrac{313-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}=-4\)
Đề sai sửa lại và làm:
Ta có:
\(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}=-4\)
\(\Leftrightarrow\left(\dfrac{315-x}{101}+1\right)+\left(\dfrac{313-x}{103}+1\right)+\left(\dfrac{311-x}{105}+1\right)+\left(\dfrac{309-x}{107}+1\right)=0\)
\(\Leftrightarrow\dfrac{416-x}{101}+\dfrac{416-x}{103}+\dfrac{416-x}{105}+\dfrac{416-x}{107}=0\)
\(\Leftrightarrow\left(416-x\right)\left(\dfrac{1}{101}+\dfrac{1}{103}+\dfrac{1}{105}+\dfrac{1}{107}\right)=0\)
\(\Leftrightarrow416-x=0\)
\(\Leftrightarrow x=416\)
VẬY....
làm như thế này đứng chưa:
315-x/101+313-x/103+311-x/105+309-x/107=-4
<=>(315-x/101+1)+(313-x/103+1)+(311-x/105+1)+(309-x/107+1)=-4+4
<=>x+416/101+x+416/103+x+416/105+x+416/107=0
<=>(x+416)(1/101+1/103+1/105+1/107)=0
<=>x+416=0
=>x={-416}
tìm x biết
\(\frac{315-x}{101}+\frac{313-x}{103}+\frac{311-x}{105}+\frac{309-x}{107}+4=0\)
GIẢI CÁC PHƯƠNG TRÌNH SAU:
a, \(\dfrac{315-x}{101}+\dfrac{313-x}{103}+\dfrac{311-x}{105}+\dfrac{309-x}{107}+4=0\)
b, \(\dfrac{x-a}{a-4}+\dfrac{x+a-1}{a+4}+\dfrac{x-a}{16-a^2}=0\)
c, \(\dfrac{x-b-c}{a}+\dfrac{x-c-a}{b}+\dfrac{x-a-b}{c}=3\)
d, \(\dfrac{x-1}{a-1}+\dfrac{1-x}{1+a}-\dfrac{2x-1}{1-a^4}=\dfrac{2a^2\left(x-1\right)}{a^4-1}\)
Nguyễn TrươngNguyễn Việt LâmNguyenTruong Viet TruongKhôi BùiAkai HarumaÁnh LêDƯƠNG PHAN KHÁNH DƯƠNGPhùng Tuệ Minhsaint suppapong udomkaewkanjana
Akai HarumaUnruly KidLê Anh DuyKhôi BùiNguyễn Việt LâmNguyễn TrươngDũng NguyễnNguyenTRẦN MINH HOÀNG
315-x /101 +313-x /103 +311-x /105 +309-x /107 =-4. Tim x
làm như thế này đứng chưa:
315-x/101+313-x/103+311-x/105+309-x/107=-4
<=>(315-x/101+1)+(313-x/103+1)+(311-x/105+1)+(309-x/107+1)=-4+4
<=>x+416/101+x+416/103+x+416/105+x+416/107=0
<=>(x+416)(1/101+1/103+1/105+1/107)=0
<=>x+416=0
=>x=-416
tại s cái bước 2 lại là x + 416/101 chứ k pải là -x+416/101
\(\frac{315-x}{101}+\frac{313-x}{103}+\frac{311-x}{105}+\frac{309-x}{107}+4=0\)=0
Tìm x nhé