a: \(\Leftrightarrow0.5x\left(\dfrac{16}{15}+\dfrac{1}{60}\right)=\dfrac{7}{60}\cdot4\cdot3\)
\(\Leftrightarrow0.5x\cdot\dfrac{13}{12}=\dfrac{7}{5}\)
\(\Leftrightarrow x=\dfrac{7}{5}:\dfrac{13}{14}=\dfrac{7}{5}\cdot\dfrac{14}{13}=\dfrac{98}{65}\)
b: \(\left|x+45-40\right|+\left|y+10-11\right|>=0\)
Dấu '=' xảy ra khi x=-5 và y=1
Bài 2: (2 điểm) Tìm x, biết:
b, \(0,5x+\dfrac{2}{3}x-x=-4\)
Tìm số nguyên x, y biết:
a, \(\dfrac{-1}{5}\)≤ \(\dfrac{x}{8}\)≤ \(\dfrac{1}{4}\)
b, \(\dfrac{4}{x-6}\)= \(\dfrac{y}{24}\)= \(\dfrac{-12}{18}\)
c, \(\dfrac{x+46}{20}\)=x \(\dfrac{2}{5}\)
1. tinh` giá trị biểu thức ( tính nhanh nếu có thế )
\(a)\frac{-6}{11}.\frac{5}{13}+\frac{-6}{11}.\frac{8}{13}-\left(\frac{-2}{5}\right)^0\) \(b)\left(2\frac{2}{3}+3\frac{1}{2}\right);\left(4\frac{3}{4}-2\frac{1}{6}\right)+\frac{19}{31}\) \(c)2,4:\left(-2\right)^3+\left(3-\frac{9}{11}\right).1\frac{3}{8}\)
\(d)\left(-\frac{3}{4}\right)^2:\frac{-3}{8}+\frac{1}{2}-\frac{3}{4}-\left(\frac{-78}{57}\right)^0\)
2. tìm x
\(a)x+\frac{-1}{5}=\left(-\frac{3}{4^{ }}\right)^2\) \(b)\left|\frac{5}{2}x+\frac{2}{3}\right|-\frac{1}{4}=0\) \(c)\frac{2}{3}x-\frac{1}{2}=\frac{5}{12}+\frac{1}{2}x\) \(d)\left(x-\frac{1}{4}\right)^4=\frac{1}{81}\)
\(e)4x+3\frac{1}{4}=x-\frac{1}{4}\) \(g)\left(x-\frac{1}{3}\right)^3=\frac{1}{27}\)
a. Tìm các số tự nhiên x, y. sao cho (2x + 1)(y –5) = 12.
b.Tìm số tự nhiên sao cho 4n-5 chia hết cho 2n-1.
c. Tìm tất cả các số B =62xy427, biết rằng số B chia hết cho 99.
\(a,\frac{3}{4}-x=1\) \(b,x+4=\frac{1}{5}\) \(c,x-\frac{1}{5}=2\)
\(d,x+\frac{5}{3}=\frac{1}{81}\) \(e,x-\frac{10}{3}=\frac{7}{15}.\frac{3}{5}\) \(g,x+\frac{3}{22}=\frac{27}{121}.\frac{11}{9}\)
\(h,1-x=\frac{49}{65}.\frac{5}{7}\) \(i,\frac{8}{23}.\frac{46}{24}-x=\frac{1}{3}\) \(k,\frac{62}{7}.x=\frac{29}{9}:\frac{3}{56}\)
Giúp mình với các bạn ơi !!! Pleasseeee help me !!!
Tìm x, y thuộc Z
a, -2x+ 3y +4y = 0
b, x2 + y2 = 2011
c, x2 + x - 2y - 4y2 = -7
Tìm x, biết:
a, \(\left(2\dfrac{3}{4}-1\dfrac{4}{5}\right)x=1\)
b, \(x^2-9\) \(3-5x=0\)
c, \(\left|3x-1\right|+2\dfrac{3}{4}=3\dfrac{1}{16}\)
\(\dfrac{x}{5}=\dfrac{3}{y}\)Tìm số nguyên x biết
\(a,\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\) ;\(b,5\frac{4}{7}:x=13\) ;\(c,\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)
\(d,\frac{2}{3}+\frac{1}{3}:x=\frac{3}{5}\) ;\(e,8\frac{2}{3}:x-10=-8\)
\(g,x+30\%x=-1,3\) ;\(i,3\frac{1}{3}x+16\frac{3}{4}=-13,25\)
\(k,\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\) ;m,/2x-1/=\(\left(-4^2\right)\)
