Question

(2x-5)^3=15^2-4.5^2, giúp mình với

Answer 1

`(2x-5)^3=15^2-4. 5^2`

`=> (2x-5)^3=225-4  . 25`

`=> (2x-5)^3=225-100`

`=> (2x-5)^3=125`

`=> (2x-5)^3=5^3`

`=>2x-5=5`

`=>2x=5+5`

`=>2x=10`

`=>x=10:2`

`=>x=5`

Vậy: `x=5`

Answer 2

\(\left(2x-5\right)^3=15^2-4\cdot5^2\\ \left(2x-5\right)^3=225-100\\ \left(2x-5\right)^3=125\\ \left(2x-5\right)^3=5^3\\ 2x-5=5\\ 2x=10\\ x=5\)