2x + 1 = 99
2x = 99 - 1
2x = 98
x = 98 : 2
x = 39
2x +1=99
2.x +1=99
2.x=99-1
2.x=98
x= 98:2
x=49
2x + 1 = 99
2x = 99 - 1
2x = 98
=> x = 49
2x+1=99
nên 2x=98
hay x=49
2x + 1 = 99
<=> 2x + 1 - 99 = 0
<=> 2x - 98 = 0
<=> 2x = 98
<=> \(x=\dfrac{98}{2}=49\)