[tex]\sqrt{15-n}[/tex]=[tex]\sqrt{\frac{n}{4}}[/tex]
Square both sides. Now
15-n=[tex]\frac{n}{4}[/tex]
Multiply both sides by 4:
4(15-n)=n
Distribute
60-4n=n
Add 4n to both sides:
60=5n
Divide both sides by 5
12=n
Check:
[tex]\sqrt{15-12}[/tex]=[tex]\sqrt{\frac{12}{4}}[/tex]
[tex]\sqrt{3}[/tex]=[tex]\sqrt{3} [/tex]
Which is true.
