Question

tìm x bt (x-7)²-(x-2)²=26 giải hộ nha. cảm ơn nhiều

Answer 1

`(x-7)^{2}-(x-2)^{2}=26`

`<=>(x-7-x+2)(x-7+x-2)=26`

`<=>-5(2x-9)=26`

`<=>2x-9=-26/5`

`<=>2x=19/5`

`<=>x=19/10`

Answer 2

\(\left(x-7\right)^2-\left(x-2\right)^2=26\)

\(< =>x^2-14x+49-\left(x-2\right)^2=26\)

\(< =>x^2-14x+49-\left(x^2-4x+4\right)=26\)

\(< =>x^2-14x+49-x^2+4x-4=26\)

\(< =>-10x+49=26+4\)

\(< =>-10x=30-49\)

\(< =>-10x=-19\)

\(< =>x=\dfrac{19}{10}\)

Answer 3

`(x-7)^{2}-(x-2)^{2}=26`

`<=>(x-7-x+2)(x-7+x-2)=26`

`<=>-5(2x-9)=26`

`<=>2x-9=-26/5`

`<=>2x=71/5`

`<=>x=71/10`