a) \(\left(x-1\right)^2=49\)
\(\Rightarrow\left(x-1\right)^2=7^2=\left(-7\right)^2\)
\(\Rightarrow x-1=7\) hoặc \(x-1=-7\)
\(x=7+1=8\) \(x=-7+1=-6\)
Vậy x = 8 hoặc x = - 6
b) \(3\cdot\left(13-x\right)^2=27\)
\(\left(13-x\right)^2=27\div3=9\)
\(\Rightarrow\left(13-x\right)^2=3^2=\left(-3\right)^2\)
\(\Rightarrow13-x=3\) hoặc \(13-x=-3\)
\(x=13-3=10\) \(x=13+3=16\)
Vậy x = 10 hoặc x = 16
c) \(164-\left(15-x\right)^3=100\)
\(\left(15-x\right)^3=164-100=64\)
\(\Rightarrow\left(15-x\right)^3=4^3\)
\(\Rightarrow15-x=4\)
\(x=15-4=11\)
Vậy x = 11
d) \(\left(x+3\right)^3-15=210\)
\(\left(x+3\right)^3=210+15=225\)
\(\Rightarrow\left(x+3\right)^3=...\)
Tương tự mũ lẻ cậu nhé
e) \(x^2\div4=16\)
\(x^2=16\cdot4=64\)
\(\Rightarrow x^2=8^2=\left(-8\right)^2\)
Vậy x = 8 hoặc x = - 8
a/\(\left(x-1\right)^2\)=49
\(\left(x-1\right)^2\)=\(7^2\)
=>x-1=7
x=7+1
x=8
b/3.\(\left(13-x\right)^2\)=27
\(\left(13-x\right)^2\)=27:3
\(\left(13-x\right)^2\)=9
\(\left(13-x\right)^2\)=\(3^2\)
=>13-x=3
x=13-3
x=10
c/164-\(\left(15-x\right)^3\)=100
\(\left(15-x\right)^3\)=164-100
\(\left(15-x\right)^3\)=64
\(\left(15-x\right)^3\)=\(4^3\)
=>15-x=4
x=15-4
x=11
d/\(\left(x+3\right)^3\)-15=210
\(\left(x+3\right)^3\)=210+15
\(\left(x+3\right)^3\)=225
sai đề bài câu d hay sao ý bạn ạ
chỉ có \(\left(x+3\right)^2\)thì mới tính được
e/\(x^2\):4=16
\(x^2\)=16.4
\(x^2\)=64
\(x^2\)=\(8^2\)
=>x=8
