The answer is -4 hope that helps :)
Answer is 9.5 First find DC by doing the Pythagorean theorem
BC is 3 BD is 5
So 3^2+ DC= 5^2
9+____=25
So DC is 4 cuz 4times 4=16
Now add AD+DC=AC
5+4=9
So BC is 3 the bottom AC is 9
3^2+9^2= 9+81=90 the sq rt of 90 is 9.5
3 to the power of 9 over 10
A and C...................