pak bu tolong d bantu ini jawabanne gimana

kalikan dengan akar sekawan,
=> (x - 4) × (5 + √(x^2+9)/(5-√(x^2+9)(5+√(x^2+9)
=> (x -4)×(5+√(x^2+9) / { 25-(x^2+9) }
=> (x-4)×(5+√(x^2+9) /(25-x^2-9)
=> (x-4)×(5+√(x^2+9) /(16 -x^2)
=> (x-4)×(5+√(x^2+9)/ -(x^2-16)
=> (x-4)×(5+√(x^2+9) / -(x-4)(x+4)
=> -(√(x^2+9) / (x +4)
lim x ->4 = -(√(x^2+9)/( x +4)
= - (√(4^2+9) / (4+4)
= - √25/8
= -5/8