Tolongin plissss no 18

pakai turunan
^ pangkat
-(2x)(1/2)(x²-7)^(1/2-1)
------------------------------
2x - 2

-x(x²-7)^-1/2
-----------------
2x - 2

{-x / √(x²-7)}
-----------------
2x - 2
masukan x = 4
{-4 / √(4²-7)}
------------------
2(4) - 2

{-4 / √9}
-----------
6

= (-4/3) ÷ 6
= -4/3 × 1/6
= -4/18
= -2/9