Question 186786
Note: {{{sqrt(-25)<>-5}}} and  {{{sqrt(-9)<>-3}}} since you CANNOT take the square root of a negative number. Instead, we denote the value {{{i=sqrt(-1)}}} where 'i' is an imaginary number.



So...


{{{sqrt(-25)*sqrt(-9)=sqrt(-1*25)*sqrt(-1*9)=sqrt(-1)*sqrt(25)*sqrt(-1)*sqrt(9)=i*5*i*3=(5*3)*(i*i)=15i^2=15(-1)=-15}}}



This means that {{{sqrt(-25)*sqrt(-9)=-15}}}



So you were off by a sign.