\(\frac{-1}{2}+\frac{1}{3}+\frac{2}{4}=\frac{-6}{12}+\frac{4}{12}+\frac{6}{12}\)
= \(\frac{4}{12}\)
\(\frac{-1}{2}+\frac{1}{3}+\frac{2}{4}=\frac{-6}{12}+\frac{4}{12}+\frac{6}{12}\)
= \(\frac{4}{12}\)
tìm x
a, \(\frac{5}{6}=\frac{-1}{x}\)
b,\(\frac{-3}{7}=\frac{x}{14}\)
c,\(\frac{x+1}{4}=\frac{-3}{2}\)
d,\(\frac{2x-3}{5}=\frac{-6}{7}\)
e,\(\frac{3-5x}{4}=\frac{5}{6}\)
f,\(\frac{12}{x}=\frac{-6}{5}\)
tìm x
a.\(\frac{3}{5}-\frac{x}{4}=\frac{7}{2}\)
b,\(\frac{x-5}{4}-\frac{3}{5}=\frac{1}{2}\)
c,\(1-\frac{8}{x}=\frac{-3}{5}\)
d,\(\frac{4}{3}=\frac{8-x}{2x+3}\)
B1, thực hiện phép tính ;
a, \(\frac{3}{-56}-\)\(\frac{-7}{64}\)
b, \(\frac{-5}{54}-\frac{11}{-36}\)
c, \(\frac{9}{28}+\)\(\frac{-2}{49}\)
d, \(\frac{-5}{-72}+\frac{7}{-48}\)
e, \(\frac{-5y}{2x^3}+\)\(\frac{2x}{3y}\)
f, \(\frac{2}{3x^4y^5}+\frac{5y^3}{2x^6}\)
tìm x,
a, \(2(x-3)-5\times(2x-4)=0\)
b,\(3+\frac{1}{x-8}=0\)
c,\(\frac{8}{3}-\frac{2x+3}{5}=-\frac{-7}{3}\)
d,\(\frac{1}{9}=\frac{5}{3x-5}=0\)
Bài 1: Thực hiện phép tính:
a) (\(\frac{4}{3}x^{n+1}\) - \(\frac{1}{2}y^{n^{ }}\) ) . 2xy - (\(\frac{2}{3}x^{n+1}\) - \(\frac{5}{6}y^{n^{ }}\)) . 7xy
1)Rút gọn biểu thức
A=\(\frac{1}{a-b}+\frac{1}{a+b}+\frac{2a}{a^2+b^2}+\frac{4a^2}{a^4+b^4}+\frac{8a^7}{a^8+b^8}\)
B=\(\frac{1}{a^2+a}+\frac{1}{a^2+3a+2}+\frac{1}{a^2+5a+6}\)
2)Cho\(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{1}{a+b+c}\).CMR \(\frac{1}{a^{2019}}+\frac{1}{b^{2019}}+\frac{1}{c^{2019}}=\frac{1}{a^{2019}+b^{2019}+c^{2019}}\)
B1, tìm x ;
a, \(\frac{x}{-4}+6=8\)
b,\(\frac{4}{-x}-7=-5\)
c,12\(+\)\(\frac{-6}{5x}=17\)
d, \(\frac{3-x}{7}=\frac{x+5}{4}\)
e,7-2x\(=\frac{-3}{3x}\)
Tính giá trị biểu thức:
A = \(2\frac{1}{309}\times\frac{1}{785}-\frac{1}{103}\times3\frac{784}{785}-\frac{4}{309\times785}+\frac{4}{103}\)
B = \(4\frac{1}{113}\times\frac{1}{371}-\frac{2}{113}\times5\frac{370}{371}-\frac{3}{113\times371}-\frac{4}{371}\)
C = \(x^3-31x^2-32x+7\) tại x = 32
D = \(\left(x-a\right)\left(x-b\right)+\left(x-b\right)\left(x-c\right)+\left(x-c\right)\left(x-a\right)-x^2\)tại x = a + b + c
Cho số thực x thỏa mãn : \(\frac{x}{x^2+x+1}=\frac{1}{4}\)
Chứng minh: x3 = 8x - 3 và tính A = \(\frac{x^5-3x^3-10x+12}{x^4+7x^2+15}\)