Toán (x+3)^3=-125 (x-4)^4=(x-4)^2 (x-4)^3=(4-x)^2 14/07/2021 By Alaia (x+3)^3=-125 (x-4)^4=(x-4)^2 (x-4)^3=(4-x)^2
a) $(x+3)^3=-125$ $↔x+3=-5$ $↔x=-5-3=-8$ b) $(x-4)^4=(x-4)^2$ $→$ Xảy ra 3 trường hợp: TH1: $x-4=-1$ $↔x=-1+4$ $↔x=-3$ TH2: $x-4=0$ $↔x=0+4$ $↔x=4$ TH3: $x-4=1$ $↔x=1+4$ $↔x=5$ c) $(x-4)^3=(4-x)^2$ $↔(x-4)^3=(x-4)^2$ $→$ Xảy ra 2 trường hợp: TH1: $x-4=0$ $↔x=4$ TH2: $x-4=1$ $↔x=5$ Trả lời
`(x+3)^3=-125` `⇔(x+3)^3=-5^3` `⇔x+3 = -5` `⇔x= -5 – 3` `⇒x=-8` _________________ `(x-4)^4=(x-4)^2` `⇔` `x-4 = 1` Hoặc `x-4 = 0` Hoặc `x -4 = -1` `⇒` `x=5` `x=4` `x=3` Vậy `x∈{3;4;5}` _____________________ `(x-4)^3=(4-x)^2` `⇔` `x-4=1` Hoặc `x-4=0` `⇒` `x=5` Hoặc `x = 4` Vậy `x ∈{4;5}` `#Study well` Trả lời