Đáp án:
Giải thích các bước giải:
7x=-14
x = -14 :7
x= -2
6x-(-5)=17
6x =17+ (-5)
6x = 12
x = 12 : 6
x = 2
(x+2)(x-9)=0
⇒\(\left[ \begin{array}{l}x+2=0\\x-9=0\end{array} \right.\) ⇔ \(\left[ \begin{array}{l}x=-2\\x=9\end{array} \right.\)
3x-5=-7-13
3x-5=-20
3x =-20+5
3x = -15
x = -15 : 3
x = -5
║x ║-10=-3
║x ║ = 7
x = 7
x ÷(-2)=9
x = -18
4x+(-8)=24
4x = 32
x = 8
(3-x)9(x+7)=0
⇒\(\left[ \begin{array}{l}3-x=0\\x+7=0\end{array} \right.\) ⇔ \(\left[ \begin{array}{l}x=3\\x=-7\end{array} \right.\)
-15 ÷x=3
x = -5
-3x+8=-7
-3x = -15
x = 5
(x-6)(7-x)=0
⇒\(\left[ \begin{array}{l}x-6=0\\7-x=0\end{array} \right.\) ⇔ \(\left[ \begin{array}{l}x=-6\\x=7\end{array} \right.\)
