\(\frac{2x-9}{240}=\frac{39}{80}\)
<=> \(\left(2x-9\right)\cdot80=240\cdot39\)
<=> \(160x-720=9360\)
<=> \(160x=10080\)
<=> \(x=63\)
\(\left|x-8\right|+12=25\)
<=> \(\left|x-8\right|=13\)
<=> x - 8 = 13 hoặc x - 8 = -13
<=> x = 21 hoặc x = -5
(2x-9):3/240:3 =39/80
2x:3-3/80=39/80
=>2x:3 =39
2x = 39:3
2x =13
x = 13 :2
x = 13/2
b)x - 8 =25 -12
x - 8 = 13
x = 13 +8
x = 21
đúng thì nhớ đó ^^