\(\dfrac{x}{3}-\dfrac{5x}{6}-\dfrac{15x}{12}=\dfrac{x}{4}-5\)
Đs. X=\(\dfrac{30}{7}\)
Bài 2:
a) (x+1)(2x-3)-3(x-2)
=2(x-1)\(^2\)
b) (x+1)(x\(^2\)-x+1)-2x
=x(x-1)(x+1)
c) \(\dfrac{x}{3}\)-\(\dfrac{5x}{6}\)-\(\dfrac{15x}{12}\)=\(\dfrac{x}{4}\)-5
d) \(\dfrac{x-1}{2}\)-\(\dfrac{x+1}{15}\)-
\(\dfrac{2x-13}{6}\)=0
e) \(\dfrac{3\left(5x-2\right)}{4}\)-2
=\(\dfrac{7x}{3}\)-5(x-7)
g) \(\dfrac{x-3}{11}\)+\(\dfrac{x+1}{3}\)
=\(\dfrac{x+7}{9}\)-1
h) \(\dfrac{3x-0,4}{2}\)+\(\dfrac{1,5-2x}{3}\)
=\(\dfrac{x+0,5}{5}\)
a) Ta có: \(\left(x+1\right)\left(2x-3\right)-3\left(x-2\right)=2\left(x-1\right)^2\)
\(\Leftrightarrow2x^2-3x+2x-3-3x+6=2\left(x^2-2x+1\right)\)
\(\Leftrightarrow2x^2-4x+3-2x^2+4x-2=0\)
\(\Leftrightarrow1=0\)(vô lý)
Vậy: \(S=\varnothing\)
a) 5(k+3x)(x+1)-4(1+2x)=80 x\(_0\)=2Tìm gt của kb) x+1=xc) x+2=0d) x+5=0e) (x+1)(2x-3)-3(x-2)=2(x-1)\(^2\)f) (x+1)(x\(^2\)-x+1)-2x=x(x-1)(x+1)g)\(\dfrac{x}{3}\)-\(\dfrac{5x}{6}\)-\(\dfrac{15x}{12}\)=\(\dfrac{x}{4}\)-5h) \(\dfrac{x-1}{2}\)-\(\dfrac{x+1}{15}\)-\(\dfrac{2x-13}{6}\)=0i) \(\dfrac{3\left(5x-2\right)}{4}\)-2=\(\dfrac{7x}{3}\)-5(x-7)
j) \(\dfrac{x-3}{11}\)+\(\dfrac{x+1}{3}\)=\(\dfrac{x+7}{9}\)-1k)\(\dfrac{3x-0,4}{2}\)+\(\dfrac{1,5-2x}{3}\)=\(\dfrac{x+0,5}{5}\)l) \(\dfrac{x-4}{5}\)+\(\dfrac{3x-2}{10}\)-x=\(\dfrac{2x-5}{3}\)-\(\dfrac{7x+2}{6}\)m) \(\dfrac{\left(2x-3\right)\left(2x+3\right)}{8}\)=\(\dfrac{\left(x-4\right)^{^2}}{6}\)+\(\dfrac{\left(x-2^{ }\right)^2}{3}\)n) \(\dfrac{7x^2-14x-5}{15}\)=\(\dfrac{\left(2x+1\right)^2}{5}\)-\(\dfrac{\left(x-1\right)^2}{3}\)o) \(\dfrac{\left(7x+1\right)\left(x-2\right)}{10}\)+\(\dfrac{2}{5}\)=\(\dfrac{\left(x-2^{ }\right)^2}{5}\)+\(\dfrac{\left(x-1\right)\left(x-2\right)}{10}\)
Chia câu hỏi ra cho thành nhiều phần cho dễ trả lời á bạn
1/ \(\dfrac{5x+1}{8}-\dfrac{x-2}{4}=\dfrac{1}{2}\)
2/ \(\dfrac{x+3}{4}+\dfrac{1-3x}{3}=\dfrac{-x+1}{18}\)
3/ \(\dfrac{x+2}{4}-\dfrac{5x}{6}=\dfrac{1-x}{3}\)
4/ \(\dfrac{x-3}{2}-\dfrac{x+1}{10}=\dfrac{x-2}{5}\)
5/ \(\dfrac{4x+1}{4}-\dfrac{9x-5}{12}+\dfrac{x-2}{3}=0\)
1: Ta có: \(\dfrac{5x+1}{8}-\dfrac{x-2}{4}=\dfrac{1}{2}\)
\(\Leftrightarrow5x+1-2\left(x-2\right)=4\)
\(\Leftrightarrow5x+1-2x+4=4\)
\(\Leftrightarrow3x=-1\)
hay \(x=-\dfrac{1}{3}\)
2: Ta có: \(\dfrac{x+3}{4}+\dfrac{1-3x}{3}=\dfrac{-x+1}{18}\)
\(\Leftrightarrow9x+27+12-36x=-2x+2\)
\(\Leftrightarrow-27x+2x=2-39\)
hay \(x=\dfrac{37}{25}\)
3: Ta có: \(\dfrac{x+2}{4}-\dfrac{5x}{6}=\dfrac{1-x}{3}\)
\(\Leftrightarrow3x+6-10x=4-4x\)
\(\Leftrightarrow-7x+4x=4-6=-2\)
hay \(x=\dfrac{2}{3}\)
4: Ta có: \(\dfrac{x-3}{2}-\dfrac{x+1}{10}=\dfrac{x-2}{5}\)
\(\Leftrightarrow5x-15-x-1=2x-4\)
\(\Leftrightarrow4x-2x=-4+16=12\)
hay x=6
5: Ta có: \(\dfrac{4x+1}{4}-\dfrac{9x-5}{12}+\dfrac{x-2}{3}=0\)
\(\Leftrightarrow12x+3-9x+5+4x-8=0\)
\(\Leftrightarrow7x=0\)
hay x=0
Bài 1 : Thực hiện phép tính:
a, \(\dfrac{6}{7}.[\left(\dfrac{-7}{5}-\dfrac{3}{2}:\dfrac{-5}{-4}\right)+\left(\dfrac{3}{2}\right)^2]\)
Bài 2 : Tìm x :
a , \(\dfrac{2}{3}:x=1,4-\dfrac{12}{5}\)
b , \(\dfrac{x}{5}=\dfrac{5}{6}+\dfrac{-19}{30}\)
Bài 3 : Lớp 6A có 40 h/s . Cuối năm xếp loại giỏi , khá , TB . Biết số h/s giỏi bằng \(\dfrac{1}{4}\)
số h/s cả lớp . Số h/s khá bằng \(\dfrac{3}{5}\)số h/s còn lại
Tính số h/s giỏi , khá , TB?
Bài 4 : Lớp 6B có h/s xếp loại giỏi , khá , TB , yếu . Số h/s giỏi chiếm \(\dfrac{1}{6}\) , số h/s khá chiếm \(\dfrac{1}{3}\)
số h/s cả lớp . Số h/s TB chiếm \(\dfrac{7}{8}\) số h/s giỏi . Còn lại là 17 h/s yếu . Tính số h/s lớp 6B
2:
a: =>2/3:x=1,4-2,4=-1
=>x=-2/3
b: =>x/5=25/30-19/30=6/30=1/5
=>x=1
3:
Số học sinh giỏi là 40*1/4=10 bạn
Số học sinh khá là 30*3/5=18 bạn
Số học sinh TB là 30-18=12 bạn
Giải phương trình sau :
a,\(\dfrac{7-3x}{12}+\dfrac{5x+2}{7}=x+13\)
b,\(\dfrac{3\left(x+3\right)}{4}-\dfrac{1}{2}=\dfrac{5x+9}{7}-\dfrac{7x-9}{4}\)
c,\(\dfrac{2x+1}{3}-\dfrac{5x+2}{7}=x+3\)
d,\(\dfrac{2x-3}{3}-\dfrac{2x+3}{7}=\dfrac{4x+3}{5}-17\)
a: \(\Leftrightarrow7\left(7-3x\right)+12\left(5x+2\right)=84\left(x+13\right)\)
\(\Leftrightarrow49-21x+60x+24=84x+1092\)
\(\Leftrightarrow39x-84x=1092-73\)
=>-45x=1019
hay x=-1019/45
b: \(\Leftrightarrow21\left(x+3\right)-14=4\left(5x+9\right)-7\left(7x-9\right)\)
=>21x+63-14=20x+36-49x+63
=>21x+49=-29x+99
=>50x=50
hay x=1
c: \(\Leftrightarrow7\left(2x+1\right)-3\left(5x+2\right)=21x+63\)
=>14x+7-15x-6-21x-63=0
=>-22x-64=0
hay x=-32/11
d: \(\Leftrightarrow35\left(2x-3\right)-15\left(2x+3\right)=21\left(4x+3\right)-17\cdot105\)
=>70x-105-30x-45=84x+63-1785
=>40x-150-84x+1722=0
=>-44x+1572=0
hay x=393/11
a, msc 12.7=84
Chuyển vế về =0 rồi làm
b,msc 28
c,làm tương tự
a, \(\Rightarrow49-21x+60x+24=84x+1092\)
\(\Leftrightarrow-45x=1019\Leftrightarrow x=-\dfrac{1019}{45}\)
b, \(\Rightarrow21\left(x+3\right)-14=4\left(5x+9\right)-7\left(7x-9\right)\)
\(\Leftrightarrow21x+63-14=20x+36-49x+63\)
\(\Leftrightarrow50x=50\Leftrightarrow x=1\)
c, \(\Rightarrow14x+7-15x-6=21x+63\Leftrightarrow-22x=62\Leftrightarrow x=-\dfrac{31}{11}\)
d, \(\Rightarrow35\left(2x-3\right)-15\left(2x+3\right)=21\left(4x+3\right)-105.17\)
\(\Leftrightarrow70x-105-30x-45=84x+63-1785\)
\(\Leftrightarrow-44x=-1572\Leftrightarrow x=\dfrac{393}{11}\)
giải phương trình sau
\(\dfrac{2x-1}{3x^2+7x+2}+\dfrac{3}{9x^2+15x+4}-\dfrac{2x+7}{3x^2-5x-12}=\dfrac{5}{x+2}\)
\(\dfrac{2x-1}{3x^2+7x+2}+\dfrac{3}{9x^2+15x+4}-\dfrac{2x+7}{3x^2-5x-12}=\dfrac{5}{x+2}\)
\(\Leftrightarrow\dfrac{2x-1}{\left(3x+1\right)\left(x+2\right)}+\dfrac{3}{\left(3x+1\right)\left(3x+4\right)}-\dfrac{2x+7}{\left(4x+3\right)\left(x-3\right)}=\dfrac{5}{x+2}\)
\(\Leftrightarrow\dfrac{1}{x+2}-\dfrac{1}{3x+1}+\dfrac{1}{3x+1}-\dfrac{1}{3x+4}+\dfrac{1}{3x+4}-\dfrac{1}{x-3}=\dfrac{5}{x+2}\)
\(\Leftrightarrow\dfrac{1}{x+2}-\dfrac{1}{x-3}=\dfrac{5}{x+2}\)
\(\Leftrightarrow\dfrac{x-3-x-2}{\left(x+2\right)\left(x-3\right)}=\dfrac{5\left(x-3\right)}{\left(x+2\right)\left(x-3\right)}\)
\(\Leftrightarrow5x-3=-5\)
\(\Leftrightarrow x=-\dfrac{2}{5}\)
Vậy...
Giải các phương trình :
a) \(\dfrac{4x+3}{5}-\dfrac{6x-2}{7}=\dfrac{5x+4}{3}+3\)
b) \(\dfrac{x+4}{5}-x+4=\dfrac{x}{3}-\dfrac{x-2}{2}\)
c)\(\dfrac{x+2}{3}+\dfrac{3\left(2x-1\right)}{4}-\dfrac{5x-3}{6}=x+\dfrac{5}{12}\)
a) \(\dfrac{4x+3}{5}-\dfrac{6x-2}{7}=\dfrac{5x+4}{3}+3\)
\(\Leftrightarrow21\left(4x+3\right)-15\left(6x-2\right)=35\left(5x+4\right)+315\)
\(\Leftrightarrow84x+63-90x+30=175x+140+315\)
\(\Leftrightarrow84x-90x-175x=140+315-63-30\)
\(\Leftrightarrow-181x=362\)
\(\Leftrightarrow x=-\dfrac{362}{181}=-2\)
Vậy: Tập ngiệm của phương trình là: \(S=\left\{-2\right\}\)
b) \(\dfrac{x+4}{5}-x+4=\dfrac{x}{3}-\dfrac{x-2}{2}\)
\(\Leftrightarrow6\left(x+4\right)-30x+120=10x-15\left(x-2\right)\)
\(\Leftrightarrow6x+24-30x-120=10x-15x+30\)
\(\Leftrightarrow6x-30x-10x+15x=30-24+120\)
\(\Leftrightarrow-19x=126\)
\(\Leftrightarrow x=-\dfrac{126}{19}\)
Vậy: Tập ngiệm của phương trình là: \(S=\left\{-\dfrac{126}{19}\right\}\)
c) \(\dfrac{x+2}{3}+\dfrac{3\left(2x-1\right)}{4}-\dfrac{5x-3}{6}=x+\dfrac{5}{12}\)
\(\Leftrightarrow4\left(x+2\right)+9\left(2x-1\right)-2\left(5x-3\right)=12x+5\)
\(\Leftrightarrow4x+8+18x-9-10x+6=12x+5\)
\(\Leftrightarrow4x+18x-10x-12x=5-8+9-6\)
\(\Leftrightarrow0x=0\)
Vậy: Tập ngiệm của phương trình là: \(S=\left\{R\right\}\)
_Chúc bạn học tốt_
trời ui
toàn pài dễ mà h phải ik học ùi chán quá à
1) \(\dfrac{5x-2}{3}\)= \(\dfrac{5-3x}{2}\)
2) \(\dfrac{x+4}{5}\) - x + 4 = \(\dfrac{x}{3}\) - \(\dfrac{x-2}{2}\)
3) \(\dfrac{10x+3}{12}\)= 1 + \(\dfrac{6+8x}{9}\)
4) \(\dfrac{x+1}{3}\)- \(\dfrac{x-2}{6}\) = \(\dfrac{2x-1}{2}\)
2) Ta có: \(\dfrac{x+4}{5}-x+4=\dfrac{x}{3}-\dfrac{x-2}{2}\)
\(\Leftrightarrow\dfrac{6\left(x+4\right)}{30}-\dfrac{30\left(x-4\right)}{30}=\dfrac{10x}{30}-\dfrac{15\left(x-2\right)}{30}\)
\(\Leftrightarrow6x+24-30x+120=10x-15x+30\)
\(\Leftrightarrow-24x+144=-5x+30\)
\(\Leftrightarrow-24x+144+5x-30=0\)
\(\Leftrightarrow-19x+114=0\)
\(\Leftrightarrow-19x=-114\)
hay x=6
Vậy: x=6
3) Ta có: \(\dfrac{10x+3}{12}=1+\dfrac{6+8x}{9}\)
\(\Leftrightarrow\dfrac{3\left(10x+3\right)}{36}=\dfrac{36}{36}+\dfrac{4\left(6+8x\right)}{36}\)
\(\Leftrightarrow30x+9=36+24+32x\)
\(\Leftrightarrow30x+9-60-32x=0\)
\(\Leftrightarrow-2x-51=0\)
\(\Leftrightarrow-2x=51\)
hay \(x=-\dfrac{51}{2}\)
Vậy: \(x=-\dfrac{51}{2}\)
4) Ta có: \(\dfrac{x+1}{3}-\dfrac{x-2}{6}=\dfrac{2x-1}{2}\)
\(\Leftrightarrow\dfrac{2\left(x+1\right)}{6}-\dfrac{x-2}{6}=\dfrac{3\left(2x-1\right)}{6}\)
\(\Leftrightarrow2x+2-x+2=6x-3\)
\(\Leftrightarrow x+4-6x+3=0\)
\(\Leftrightarrow-5x+7=0\)
\(\Leftrightarrow-5x=-7\)
hay \(x=\dfrac{7}{5}\)
Vậy: \(x=\dfrac{7}{5}\)
1) \(\dfrac{5x-2}{3}=\dfrac{5-3x}{2}\)
\(2\left(5x-2\right)=3\left(5-3x\right)\)
\(10x-4=15-9x\)
\(10x+9x=15+4\)
\(19x=19\)
\(x=1\)
Vậy \(x=1\)
2) Ta có: ⇔6(x+4)30−30(x−4)30=10x30−15(x−2)30⇔6(x+4)30−30(x−4)30=10x30−15(x−2)30
⇔6x+24−30x+120=10x−15x+30⇔6x+24−30x+120=10x−15x+30
⇔−24x+144=−5x+30⇔−24x+144=−5x+30
⇔−24x+144+5x−30=0⇔−24x+144+5x−30=0
⇔−19x+114=0⇔−19x+114=0
⇔−19x=−114⇔−19x=−114
hay x=6
Vậy: x=6
3) Ta có: ⇔3(10x+3)36=3636+4(6+8x)36⇔3(10x+3)36=3636+4(6+8x)36
⇔30x+9=36+24+32x⇔30x+9=36+24+32x
⇔30x+9−60−32x=0⇔30x+9−60−32x=0
⇔−2x−51=0⇔−2x−51=0
⇔−2x=51⇔−2x=51
hay x=−512x=−512
4) Ta có: ⇔2(x+1)6−x−26=3(2x−1)6⇔2(x+1)6−x−26=3(2x−1)6
⇔2x+2−x+2=6x−3⇔2x+2−x+2=6x−3
⇔x+4−6x+3=0⇔x+4−6x+3=0
⇔−5x+7=0⇔−5x+7=0
⇔−5x=−7⇔−5x=−7
hay x=75
bài 3: giải phương trình
a) \(\dfrac{5x-7
}{3}=\dfrac{5-3x}{2}\)
b) \(\dfrac{10x+3}{12}=1+\dfrac{6+8x}{9}\)
c) \(\dfrac{7x-1}{6}+2x=\dfrac{16-x}{5}\)
d) \(4\left(0,5-1,5x\right)=-\dfrac{5x-6}{3}\)
a: =>10x-14=15-9x
=>19x=29
hay x=29/19
b: \(\Leftrightarrow3\left(10x+3\right)=36+4\left(8x+6\right)\)
=>30x+9=36+32x+24
=>30x+9=32x+60
=>-2x=51
hay x=-51/2
c: \(\Leftrightarrow5\left(7x-1\right)+60x=6\left(16-x\right)\)
=>35x-5+60x=96-6x
=>101x=101
hay x=1
d: \(\Leftrightarrow12\left(\dfrac{1}{2}-\dfrac{3}{2}x\right)=-5x+6\)
\(\Leftrightarrow6-18x+5x-6=0\)
=>-13x=0
hay x=0
\(a,\dfrac{5x-7}{3}=\dfrac{5-3x}{2}\\ \Leftrightarrow2\left(5x-7\right)=3\left(5-3x\right)\\ \Leftrightarrow10x-14=15-9x\\ \Leftrightarrow10x-14-15+9x=0\\ \Leftrightarrow19x-19=0\\ \Leftrightarrow x=1\)
\(b,\dfrac{10x+3}{12}=1+\dfrac{6+8x}{9}\\ \Leftrightarrow\dfrac{3\left(10x+3\right)}{36}=\dfrac{36}{36}+\dfrac{4\left(6+8x\right)}{36}\\ \Leftrightarrow30x+9=36+24+32x\\ \Leftrightarrow36+24+32x-30x-9=0\\ \Leftrightarrow2x+51=0\\ \Leftrightarrow x=-\dfrac{51}{2}\)
\(c,\dfrac{7x-1}{6}+2x=\dfrac{16-x}{5}\\ \Leftrightarrow\dfrac{7x-1+12x}{6}=\dfrac{16-x}{5}\\ \Leftrightarrow5\left(19x-1\right)=6\left(16-x\right)\\ \Leftrightarrow95x-5=96-6x\\ \Leftrightarrow95x-5-96+6x=0\\ \Leftrightarrow101x-101=0\\ \Leftrightarrow x=1\)
\(d,4\left(0,5-1,5x\right)=-\dfrac{5x-6}{3}\\ \Leftrightarrow12\left(0,5-1,5x\right)=6-5x\\ \Leftrightarrow6-18x=6-5x\\ \Leftrightarrow6-5x-6+18x=0\\ \Leftrightarrow13x=0\\ \Leftrightarrow x=0\)