Toán Tìm x : (2x-1):(2x-1) = 27 (x+1):(x+1):(x+1) =4 01/08/2021 By Emery Tìm x : (2x-1):(2x-1) = 27 (x+1):(x+1):(x+1) =4
(2x-1)^4:(2x-1) = 27 (2x-1)^4-1 = 27 (2x-1)^3 = 27 (2x-1)^3 = 3^3 => 2x-1 = 3 2x = 3+1 2x = 4 x = 4÷2 x = 2 (x+1)^3:(x+1) =4 (x+1)^3-1 =4 (x+1)^2 =4 (x+1)^2 = 2^2 => x+1 =2 x = 2-1 x = 1 Trả lời
Giải thích các bước giải: $(2x-1)^4:(2x-1)=27$ $⇔ (2x-1)^{4-1}=27$ $⇔ (2x-1)^3=3^3$ $⇔ 2x-1=3$ $⇔ 2x=4$ $⇔ x=2$ $\text{Vậy $x=2$}$ b/ $(x+1)^3:(x+1)=4$ $⇔ (x+1)^{3-1}=4$ $⇔ (x+1)^2=(±2)^2$ $⇔ x+1=±2$ $⇔ \left[ \begin{array}{l}x=1\\x=-3\end{array} \right.$ $\text{Vậy $\left[ \begin{array}{l}x=1\\x=-3\end{array} \right.$}$ Chúc bạn học tốt !!! Trả lời
(2x-1)^4:(2x-1) = 27
(2x-1)^4-1 = 27
(2x-1)^3 = 27
(2x-1)^3 = 3^3
=> 2x-1 = 3
2x = 3+1
2x = 4
x = 4÷2
x = 2
(x+1)^3:(x+1) =4
(x+1)^3-1 =4
(x+1)^2 =4
(x+1)^2 = 2^2
=> x+1 =2
x = 2-1
x = 1
Giải thích các bước giải:
$(2x-1)^4:(2x-1)=27$
$⇔ (2x-1)^{4-1}=27$
$⇔ (2x-1)^3=3^3$
$⇔ 2x-1=3$
$⇔ 2x=4$
$⇔ x=2$
$\text{Vậy $x=2$}$
b/ $(x+1)^3:(x+1)=4$
$⇔ (x+1)^{3-1}=4$
$⇔ (x+1)^2=(±2)^2$
$⇔ x+1=±2$
$⇔ \left[ \begin{array}{l}x=1\\x=-3\end{array} \right.$
$\text{Vậy $\left[ \begin{array}{l}x=1\\x=-3\end{array} \right.$}$
Chúc bạn học tốt !!!