Tìm x

- Hướng dẫn giải

a, ${\left(x-1\right)}^2=36$

ó ${\left(x-1\right)}^2=6^2$

ó x – 1 = 6

ó x = 7

Vậy x = 7

b, ${\left(7x-11\right)}^3=2^5.5^2+200$

=> ${\left(7x-11\right)}^3=800+200$

=> ${\left(7x-11\right)}^3=1000$

=> ${\left(7x-11\right)}^3={10}^3$

=> 7x – 11 = 10

=> 7x = 21

=> x = 3

Vậy x = 3

c, $x^{11}=x$

=> $x^{11}-x=0$

=> $x(x^{10}-1)=0$

=>

d, $x^2=2^3+3^2+4^3$

=> $x^2=81$

=> x = 9

e, $\frac{2x^3}{3^2}=48$

=> $\frac{2x^3}{9}=48$

=> $2x^3=48.9$

=> $x^3=216$

=> $x^3=6^3$

=> x = 6

f, ${\left(2x+1\right)}^3=125$

=> ${\left(2x+1\right)}^3=5^3$

=> 2x + 1 = 5

=> 2x = 4

=> x = 2