Toán Lớp 6: b) – 4x – 100 : 20 = 19.
c) (x – 23) . (14 + x) = 0.
Toán Lớp 6: b) – 4x – 100 : 20 = 19. c) (x – 23) . (14 + x) = 0.
By Melanie
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b ) -4x – 100 : 20 = 19=> -4x – 5 = 19=> -4x = 19 + 5=> -4x = 24=> x = 24 : (-4)=> x = -6Vậy x = -6c ) (x – 23) . (14 + x) = 0=>\(\left[ \begin{array}{l}x – 23=0\\14 + x = 0\end{array} \right.\)=>\(\left[ \begin{array}{l}x = 23 \\x = -14\end{array} \right.\)Vậy x ∈ {23 ; -14}#dtkc
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b, -4x – 100 : 20 = 19-4x – 5 = 19-4x = 19 + 5-4x = 24x = 24 : (-4)x = -6c, (x – 23) . (14 + x) =0x – 23 = 0 hoặc 14 + x = 0x = 0 + 23 x = 0 – 14x = 23 x = -14⇒ $x_{1}$ = 23 ; $x_{2}$ = -14