Đại số lớp 7
Các câu hỏi tương tự
Tìm y biết:
a) 2y . (y - dfrac{1}{7}) 0
b) -dfrac{2}{5}+dfrac{2}{3}y+dfrac{1}{6}ydfrac{-4}{15}
Tìm các số x thỏa mãn:
a) x.left(x-dfrac{4}{7}right)0
b)left(x-dfrac{2}{5}x^2right) 0
c)left(x-dfrac{2}{5}right).left(x+dfrac{3}{7}right)0
d)left(x-dfrac{2}{5}right).left(x+dfrac{3}{7}right).left(x+dfrac{3}{4}right)0
(* dấu . là dấu nhân nha bạn ^-^)
Đọc tiếp
Tìm y biết:
a) 2y . (y - \(\dfrac{1}{7}\)) = 0
b) \(-\dfrac{2}{5}+\dfrac{2}{3}y+\dfrac{1}{6}y=\dfrac{-4}{15}\)
Tìm các số x thỏa mãn:
a) \(x.\left(x-\dfrac{4}{7}\right)>0\)
b)\(\left(x-\dfrac{2}{5}x^2\right)< 0\)
c)\(\left(x-\dfrac{2}{5}\right).\left(x+\dfrac{3}{7}\right)>0\)
d)\(\left(x-\dfrac{2}{5}\right).\left(x+\dfrac{3}{7}\right).\left(x+\dfrac{3}{4}\right)>0\)
(* dấu . là dấu nhân nha bạn ^-^)
1) tìm x:
\(\left(\dfrac{1}{7}x-\dfrac{2}{7}\right)\left(-\dfrac{1}{5}x+\dfrac{3}{5}\right)\left(\dfrac{1}{3}x+\dfrac{4}{3}\right)=0\)
tim x , biet :
a) x + dfrac{3}{10} dfrac{-2}{5}
b) x + dfrac{5}{6} dfrac{2}{5} - left(-dfrac{2}{3}right)
c) 1dfrac{2}{5} x + dfrac{3}{7} -dfrac{4}{5}
d) left[x+dfrac{3}{4}right]-dfrac{1}{3}0
e) left[x+dfrac{4}{15}right]-left[-3,75right]-left[-2,15right]
f) left(x-2right)^21
g) left(2x-1right)^3-27
h) dfrac{x-1}{-15}dfrac{-60}{x-1}
i) x : left(dfrac{-1}{2}right)^3dfrac{-1}{2}
j) left(dfrac{3}{4}right)^5.xleft(dfrac{3}{4}right)^7
k) 8^x:2^x4
Đọc tiếp
tim x , biet :
a) x + \(\dfrac{3}{10}\)= \(\dfrac{-2}{5}\)
b) x + \(\dfrac{5}{6}\) = \(\dfrac{2}{5}\) - \(\left(-\dfrac{2}{3}\right)\)
c) \(1\dfrac{2}{5}\) x + \(\dfrac{3}{7}\) = \(-\dfrac{4}{5}\)
d) \(\left[x+\dfrac{3}{4}\right]-\dfrac{1}{3}=0\)
e) \(\left[x+\dfrac{4}{15}\right]-\left[-3,75\right]=-\left[-2,15\right]\)
f) \(\left(x-2\right)^2=1\)
g) \(\left(2x-1\right)^3=-27\)
h) \(\dfrac{x-1}{-15}=\dfrac{-60}{x-1}\)
i) x : \(\left(\dfrac{-1}{2}\right)^3=\dfrac{-1}{2}\)
j) \(\left(\dfrac{3}{4}\right)^5.x=\left(\dfrac{3}{4}\right)^7\)
k) \(8^x:2^x=4\)
b) -x - 2 = \(\dfrac{5}{4}\) c) \(\dfrac{4}{3}-\left(x-\dfrac{1}{5}\right)=\left|\dfrac{-3}{10}+\dfrac{1}{2}\right|-\dfrac{1}{6}\) d) \(\dfrac{1}{3}-\left(\dfrac{2}{3}-x+\dfrac{5}{4}\right)=\dfrac{7}{12}-\left(\dfrac{5}{2}-\dfrac{13}{6}\right)\)
Tìm x biết:
a) dfrac{-32}{left(-2right)^x}4 f) left(3x-1right)^3dfrac{-8}{27}
b) left(dfrac{1}{2}right)^{2x-1}dfrac{1}{8} g) left(2x+3right)^2dfrac{9}{121}
c) dfrac{1}{9}.27^x3^x h) 5^x+5^{x+2}650
d) 9^x:3^3dfrac{1}{243} i) left(x-7right)^{x+1}-left(x-7right)0
e) dfrac{x7}{81}27...
Đọc tiếp
Tìm x biết:
a) \(\dfrac{-32}{\left(-2\right)^x}=4\) f) \(\left(3x-1\right)^3=\dfrac{-8}{27}\)
b) \(\left(\dfrac{1}{2}\right)^{2x-1}=\dfrac{1}{8}\) g) \(\left(2x+3\right)^2=\dfrac{9}{121}\)
c) \(\dfrac{1}{9}.27^x=3^x\) h) \(5^x+5^{x+2}=650\)
d) \(9^x:3^3=\dfrac{1}{243}\) i) \(\left(x-7\right)^{x+1}-\left(x-7\right)=0\)
e) \(\dfrac{x7}{81}=27\) m) \(\left(\dfrac{-3}{4}\right)^{3x-1}=\dfrac{256}{81}\)
Tìm x biết :
\(\dfrac{3}{\left(x+2\right)\cdot\left(x+5\right)}+\dfrac{5}{\left(x+5\right)\cdot\left(x+10\right)}+\dfrac{7}{\left(x+10\right)\cdot\left(x+17\right)}=\dfrac{x}{\left(x+2\right)\cdot\left(x+17\right)}\) Vs x \(\notin\){-2;-5;-17;-10}
Bài 1: Cho đơn thức
Ax^2.left(dfrac{-5}{4}x^2yright)left(dfrac{2}{5}x^3y^4right)
Bleft(dfrac{-3}{4}x^4y^4right)left(xy^2right)left(dfrac{-8}{9}x^2y^5right)
Biết A0, thì B mang dấu gì ?
Bài 2: Cho đa thức
A(x)left(x^2-5x+7right)^4left(x^2-3x+3right)^{20}
Tính tổng các hệ số trong đa thức ?
Đọc tiếp
Bài 1: Cho đơn thức
A=\(x^2.\left(\dfrac{-5}{4}x^2y\right)\left(\dfrac{2}{5}x^3y^4\right)\)
B=\(\left(\dfrac{-3}{4}x^4y^4\right)\left(xy^2\right)\left(\dfrac{-8}{9}x^2y^5\right)\)
Biết A>0, thì B mang dấu gì ?
Bài 2: Cho đa thức
A(x)=\(\left(x^2-5x+7\right)^4\left(x^2-3x+3\right)^{20}\)
Tính tổng các hệ số trong đa thức ?
a: (x-1) ( x+5) > 0
b: (x-1) ( x+5) < 0
c) \(\left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
d)\(\dfrac{3}{4}-\dfrac{1}{4}\left|x-\dfrac{1}{7}\right|=\dfrac{1}{4}\)
e) 8 ( x+1) - 2 ( 2x + 5 ) = 0
g) ( 6x-1) - ( x + 8 ) =0
h) \(\left|7x-\dfrac{1}{4}\right|=1\)
x) -2x-3=-x+7
Bài 1: Tìm x, biết :
a, dfrac{11}{13} - (dfrac{5}{42} - x ) - (dfrac{15}{28}- dfrac{11}{15})
b, |x+dfrac{4}{15}| - |-3,75| - left|-2,15right|
c, dfrac{5}{3} - left|x-dfrac{3}{2}right| dfrac{-1}{2}
d,left(x-dfrac{2}{3}right). left(2x-dfrac{3}{2}right) 0
BÀi 3: Tìm x,y biết
a, left(x^2-4right)^2+ left(x+2^{ }right)^2 0
b, left(x-y^{ }right)^2 + left|y+2right| 0
c, left|x-yright|+ left|y+dfrac{9}{25}right| 0
d, left|dfrac{1}{2}-dfrac{1}{3}+xright| left(-dfrac{1}{4}right)- left|yright|
Đọc tiếp
Bài 1: Tìm x, biết :
a, \(\dfrac{11}{13}\) - \((\dfrac{5}{42}\) - x \()\) = - \((\)\(\dfrac{15}{28}\)- \(\dfrac{11}{15}\)\()\)
b, \(|x+\dfrac{4}{15}|\) - \(|-3,75|\)= - \(\left|-2,15\right|\)
c, \(\dfrac{5}{3}\) - \(\left|x-\dfrac{3}{2}\right|\) = \(\dfrac{-1}{2}\)
d,\(\left(x-\dfrac{2}{3}\right)\). \(\left(2x-\dfrac{3}{2}\right)\) = 0
BÀi 3: Tìm x,y biết
a, \(\left(x^2-4\right)^2\)+ \(\left(x+2^{ }\right)\)\(^2\) = 0
b, \(\left(x-y^{ }\right)^2\) + \(\left|y+2\right|\) = 0
c, \(\left|x-y\right|\)+ \(\left|y+\dfrac{9}{25}\right|\)= 0
d, \(\left|\dfrac{1}{2}-\dfrac{1}{3}+x\right|\)= \(\left(-\dfrac{1}{4}\right)\)- \(\left|y\right|\)