a) 4x-11=8x-24
⇔ 4x-8x=-24+11
⇔ -4x=-13
⇔ x=$\frac{13}{4}$
b) 15-3x=2x+ 20
⇔ -3x-2x=20-15
⇔ -5x=5
⇔ x=-1
c) (x+6) ² - ( x-2)(X+2)=0
⇔ x² + 12x + 36 - x² + 4=0
⇔ 12x+40=0
⇔ 12x=40
⇔ x=$\frac{40}{12}$ =$\frac{10}{3}$
d) (4x-5)(4x+1)-(4x-3)^2= 0
⇔ 16x² + 4x - 20x - 5 - 16x² + 24x -9=0
⇔ 8x - 14 = 0
⇔ 8x = 14
⇔ x = $\frac{7}{4}$
e) (2x-5)(3x+1)-6(x-2)(x+2) = 0
⇔ 6x² + 2x - 15x - 5 - 6x² + 24 = 0
⇔ -13x +19 = 0
⇔ -13x = -19
⇔ x = $\frac{13}{19}$
f) (x-3)(x+3)- (x-1) ²=0
⇔ x² - 9 - x² + 2x - 1 = 0
⇔ 2x - 10 = 0
⇔ 2x = 10
⇔ x = 5
g) 4x - $\frac{1}{9}$ - $\frac{2x}{3}$ = $\frac{1}{6}$ - $\frac{3x}{2}$
⇔ 4x - $\frac{2x}{3}$ + $\frac{3x}{2}$ = $\frac{1}{6}$ + $\frac{1}{9}$
⇔ $\frac{24x-4x+9x}{6}$ = $\frac{3+2}{18}$
⇔ $\frac{29x}{6}$ = $\frac{5}{18}$
⇔ $\frac{87x}{18}$ = $\frac{5}{18}$
⇔ 87x = 5
⇔ x = $\frac{5}{87}$
h)4 - $\frac{3x}{6}$ - 2x = $\frac{3}{4}$ - 1 + $\frac{5x}{3}$
⇔ $\frac{-3x}{6}$ - 2x - $\frac{5x}{3}$ = $\frac{3}{4}$ - 1 - 4
⇔ $\frac{-3x - 12x -10x}{6}$ = $\frac{3 - 4 - 16}{4}$
⇔ $\frac{-25x}{6}$ = $\frac{-17}{4}$
⇔ $\frac{-50x}{12}$ = $\frac{-51}{12}$4x
⇔ 50x = 51
⇔ x = 51/50
i) 2/3.( 1-2x) = 3/4-5/6.( 2x+3)
⇔ 2/3 - 4x/3 = 3/4 - 5x/3 - 5/2
⇔ -4x/3 + 5x/3 = 3/4 - 5/2 - 2/3
⇔ x/3 = -29/12
⇔ 4x/12 = -29/12
⇔ 4x = -29
⇔ x = -29/4
i) 4/9(2x+3) - 1/2 = x - 5/6(4x-1)
⇔ 8x/9 + 4/3 - 1/2 = x - 10x/3 + 5/6
⇔ 8x/9 + 10x/3 - x = 5/6 -4/3 + 1/2
⇔ 8x+30x-9x/9 = 0
⇔ 29x = 0
⇔ x=0
Xin ctlhn ạ!
