Answer:
20
Step-by-step explanation:
AB= √5²+10²=√125
AN= √(5+x)²-125= √x²+10x-100
AB*AN= 10*(x+5) - both sides represent the area of the triangle
- √125*(x²+10x-100)=10(x+5)
- 125(x²+10x-100)=100(x²+10x+25)
- 1.25x²+12.5x-125=x²+10x+25
- 0.25x²+2.5x-150=0
- x²+10x-600=0
- x=20
