a. ( x-7) + 11 = 3
b. ( x+8) . ( x2 -16) =0
x2 là x mũ 2
c. 4.( x-6) -5.( x-2)= -7
a. ( x-7) + 11 = 3 b. ( x+8) . ( x2 -16) =0 x2 là x mũ 2 c. 4.( x-6) -5.( x-2)= -7
By Jasmine
By Jasmine
a. ( x-7) + 11 = 3
b. ( x+8) . ( x2 -16) =0
x2 là x mũ 2
c. 4.( x-6) -5.( x-2)= -7
@isa
`a. ( x-7) + 11 = 3`
`⇔ x – 7 = 3 – 11`
`⇔ x – 7 = – 8`
`⇔ x = -8 + 7`
`⇔ x = -1`
Vậy `x = -1`
`b. ( x+8) . ( x² -16) =0`
`⇔ (x + 8) . (x – 4). (x + 4) = 0`
`⇔` \(\left[ \begin{array}{l}x + 8=0\\x-4=0\\x +4=0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=-8\\x=4\\x=-4\end{array} \right.\)
Vậy `x ∈ { -8 ; 4 ; -4}`
`c, 4.( x-6) -5.( x-2)= -7`
`⇔ 4x – 24 – 5x + 10 = -7`
`⇔ -x -14 = -7`
`⇔ -x = 7`
`x = -7`
Vậy `x = -7`
$(x-7)+11=3$
$⇒x-7+11=3$
$⇒x=-1$
b, $(x+8)(x²-16)=0$
$⇒(x+8)(x-4)(x+4)=0$
⇒\(\left[ \begin{array}{l}x+8=0\\x+4=0\\x-4=0\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=-8\\x=-4\\x=4\end{array} \right.\)
c, $4(x-6)-5(x-2)=-7$
$⇒4x-24-5x+10=-7$
$⇒-x=7$
$⇒x=-7$