Answer:
3 sqrt(10)
Step-by-step explanation:
To find the distance, we use the formula
d = sqrt( ( x2-x1)^2 + (y2-y1)^2)
= sqrt( ( 2- -1)^2 + ( -4-5)^2)
= sqrt( (2+1)^2 +(-4-5)^2)
= sqrt( 3^2 +(-9)^2)
= sqrt( 9+81)
= sqrt(90)
= sqrt ( 9*10)
3 sqrt(10)