cách làm
a, 1/4+3/4.x=2
b, 2/3+4/3:x=1
c, hỗn số 3 1/4:0,5=2x:0,02
d, x+1/2=1/6
e, |x-1|-5=-2
f,| x-1/3|+1=7/3
g, (3x-1) mủ 2 -2 =7
h, (5x-2) mủ 3+1=28
cách làm
a, 1/4+3/4.x=2
b, 2/3+4/3:x=1
c, hỗn số 3 1/4:0,5=2x:0,02
d, x+1/2=1/6
e, |x-1|-5=-2
f,| x-1/3|+1=7/3
g, (3x-1) mủ 2 -2 =7
h, (5x-2) mủ 3+1=28
Đáp án:
h) x=1
Giải thích các bước giải:
\(\begin{array}{l}
a)\dfrac{1}{4} + \dfrac{3}{4}x = 2\\
\to \dfrac{3}{4}x = \dfrac{7}{4}\\
\to x = \dfrac{7}{3}\\
b)\dfrac{2}{3} + \dfrac{4}{{3x}} = 1\\
\to \dfrac{4}{{3x}} = \dfrac{1}{3}\\
\to 3x = 12\\
\to x = 4\\
c)\dfrac{{13}}{4}:\dfrac{1}{2} = 2x:\dfrac{1}{{50}}\\
\to \dfrac{{13}}{2}.\dfrac{1}{{50}} = 2x\\
\to 2x = \dfrac{{13}}{{100}}\\
\to x = \dfrac{{13}}{{200}}\\
d)x + \dfrac{1}{2} = \dfrac{1}{6}\\
\to x = – \dfrac{1}{3}\\
e)\left| {x – 1} \right| = 5 – 2\\
\to \left| {x – 1} \right| = 3\\
\to \left[ \begin{array}{l}
x – 1 = 3\\
x – 1 = – 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 4\\
x = – 2
\end{array} \right.\\
f)\left| {x – \dfrac{1}{3}} \right| + 1 = \dfrac{7}{3}\\
\to \left| {x – \dfrac{1}{3}} \right| = \dfrac{4}{3}\\
\to \left[ \begin{array}{l}
x – \dfrac{1}{3} = \dfrac{4}{3}\\
x – \dfrac{1}{3} = – \dfrac{4}{3}
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = \dfrac{5}{3}\\
x = – 1
\end{array} \right.\\
g){\left( {3x – 1} \right)^2} = 9\\
\to \left| {3x – 1} \right| = 3\\
\to \left[ \begin{array}{l}
3x – 1 = 3\\
3x – 1 = – 3
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = \dfrac{4}{3}\\
x = – \dfrac{2}{3}
\end{array} \right.\\
h){\left( {5x – 2} \right)^3} = 27\\
\to 5x – 2 = 3\\
\to x = 1
\end{array}\)