Trắc ngiệm:
1.D
2.C
3.B
4.D
5.C
6.A
7.A
8.B
9.D
10.D
Tự luận:
a) 2x+3 = 7
<=> 2x = 4
<=> x=2
b) 2x-4=x+6
<=> 2x-x = 6+4
<=> x = 10
c) x(x+3)=0
<=>\(\left[ \begin{array}{l}x=0\\x+3=0\end{array} \right.\)
<=>\(\left[ \begin{array}{l}x=0\\x=-3\end{array} \right.\)
d) (x-2)(3x+9)=0
<=> 3(x-2)(x+3)=0
<=> (x-2)(x+3)=0
<=>\(\left[ \begin{array}{l}x-2=0\\x+3=0\end{array} \right.\)
<=>\(\left[ \begin{array}{l}x=2\\x=-3\end{array} \right.\)
