Answer: 5
Step-by-step explanation:
[tex]\sqrt{4x+5}-\sqrt{x-1}=\sqrt{x+4}\\\\(\sqrt{4x+5}-\sqrt{x-1})^2=(\sqrt{x+4})^2\\\\4x+5-2\sqrt{(4x+5)(x-1)}+x-1=x+4\\\\5x+4-2\sqrt{(4x+5)(x-1)}=x+4\\\\4x=2\sqrt{(4x+5)(x-1)}\\\\2x=\sqrt{(4x+5)(x-1)}\\\\(2x)^2=(\sqrt{(4x+5)(x-1)})^2\\\\4x^2=(4x+5)(x-1)\\\\4x^2=4x^2+x-5\\\\0=x-5\\\\5=x\\\\\\Check:\\\sqrt{4(5)+5}-\sqrt{(5)-1}=\sqrt{(5)+4}\\\\\sqrt{25}-\sqrt{4}=\sqrt9\\\\5-2=3\ \checkmark[/tex]
