Question

(Х-3)(х+7)-(х+7)(9-х)=0
Помогите срочно

Answer 1

$\displaystyle\bf\\(x-3)(x+7)-(x+7)(9-x)=0\\\\(x+7)\cdot(x-3-9+x)=0\\\\(x+7)\cdot(2x-12)=0\\\\2\cdot(x+7)\cdot(x-6)=0 \ |:2\\\\(x+7)\cdot(x-6)=0\\\\\\\left[\begin{array}{ccc}x+7=0\\x-6=0\end{array}\right \\\\\\\left[\begin{array}{ccc}x_{1} =-7\\x_{2} =6\end{array}\right\\\\\\Otvet \ : \ -7 \ ; \ 6$

Answer 2

Відповідь:

x= -7 або 6

Пояснення:

(x-3)•(x+7)-(x+7)•(9-x)=0

(x+7)•(x-3-9+x)=0

(x+7)•(2•x-12)=0

2•(x+7)•(x-6)=0:2
(x+7)•(x-6)=0

{

x+7=0

x-6=0

}
{

x = -7

x = 6
}