Question

Bài 2. Giải các phương trình sau

a, \(\frac{x}{3}-\frac{5x}{6}-\frac{15x}{12}=\frac{x}{4}-5\)

b, \(\frac{8x-3}{4}-\frac{3x-2}{2}=\frac{2x-1}{2}+\frac{x+3}{4}\)

c, \(\frac{x-1}{2}-\frac{x+1}{15}-\frac{2x-13}{6}=0\)

d,\(\frac{3\left(3-x\right)}{8}+\frac{2\left(5-x\right)}{3}=\frac{1-x}{2}-2\)

e, \(\frac{3\left(5x-2\right)}{4}-2=\frac{7x}{3}-5\left(x-7\right)\)

f, \(\frac{x+5}{2}+\frac{3-2x}{4}=x-\frac{7+x}{6}\)

g, \(\frac{x-3}{11}+\frac{x+1}{3}=\frac{x+7}{9}-1\)

h, \(\frac{3x-0,4}{2}+\frac{1,5-2x}{3}=\frac{x+0,5}{5}\)

Answer 1

a)

\(\frac{x}{3}-\frac{5x}{6}-\frac{15x}{12}=\frac{x}{4}-5\)

\(\Leftrightarrow\frac{4x-10x-15x}{12}=\frac{3x-60}{12}\)

\(\Leftrightarrow\frac{-10x-11}{12}=\frac{3x-60}{12}\)

\(\Leftrightarrow\frac{-10x-11-3x+60}{12}=0\)

\(\Leftrightarrow\frac{49-13x}{12}=0\)

\(\Rightarrow49-13x=0\)

\(\Rightarrow x=\frac{-49}{13}\)

Answer 2

b)

\(\frac{8x-3}{4}-\frac{3x-2}{2}=\frac{2x-1}{2}+\frac{x+3}{4}\)

\(\Leftrightarrow\frac{8x-3-6x+4}{4}=\frac{4x-2+x+3}{4}\)

\(\Leftrightarrow\frac{2x+1}{4}=\frac{5x+1}{4}\)

\(\Leftrightarrow\frac{2x+1-5x-1}{4}=0\)

\(\Leftrightarrow\frac{-3x}{4}=0\)

\(\Rightarrow-3x=0\)

\(\Rightarrow x=0\)

Answer 3

e)

\(\frac{3\cdot\left(5x-2\right)}{4}-2=\frac{7x}{3}-5\cdot\left(x-7\right)\)

\(\Leftrightarrow\frac{45x-18-24-28x+60x-420}{12}=0\)

\(\Leftrightarrow\frac{77x-462}{12}=0\)

\(\Rightarrow77x-462=0\)

\(\Rightarrow x=\frac{462}{77}=6\)

Answer 4

f)

\(\frac{x+5}{2}+\frac{3-2x}{4}=x-\frac{7+x}{6}\)

\(\Leftrightarrow\frac{6x+30+9-6x-12x+14+2x}{12}=0\)

\(\Leftrightarrow\frac{53-10x}{12}=0\)

\(\Rightarrow53-10x=0\)

\(\Rightarrow x=\frac{-53}{10}\)

Answer 5

g)

\(\frac{x-3}{11}+\frac{x+1}{3}=\frac{x+7}{9}-1\)

\(\Leftrightarrow\frac{9x-27+33x+33-11x-77+99}{99}=0\)

\(\Leftrightarrow\frac{31x+28}{99}=0\)

\(\Rightarrow31x+28=0\)

\(\Rightarrow x=\frac{-28}{31}\)

Answer 6

h)

\(\frac{3x-0.4}{2}+\frac{1.5-2x}{3}=\frac{x+0.5}{5}\)

\(\Leftrightarrow\frac{45x-6+15-20x-6x-3}{30}=0\)

\(\Leftrightarrow\frac{19x+6}{30}=0\)

\(\Rightarrow19x+6=0\)

\(\Rightarrow x=\frac{-6}{19}\)

Answer 7

tick cho mình nha!!

Answer 8

c)

\(\frac{x-1}{2}-\frac{x+1}{15}-\frac{2x-13}{6}=0\)

\(\Leftrightarrow\frac{15x-15-2x-2-10x+65}{30}=0\)

\(\Leftrightarrow\frac{3x+50}{30}=0\)

\(\Rightarrow3x+50=0\)

\(\Rightarrow x=\frac{-50}{3}\)

Answer 9

d)

\(\frac{3\cdot\left(3-x\right)}{8}+\frac{2\cdot\left(5-x\right)}{3}=\frac{1-x}{2}-2\)

\(\Leftrightarrow\frac{27-9x+80-16x-12+12x+48}{24}=0\)

\(\Leftrightarrow\frac{-13x+143}{24}=0\)

\(\Rightarrow-13x+143=0\)

\(\Rightarrow x=\frac{-143}{-13}=11\)