The equation (x-1)^2+(y-3)^2=r^2 represents circle a. The point B (4,7) lies on the circle. What is r, The length of the radius of circle a

r=5

Step-by-step explanation:

centre is (1,3)

r=√((4-1)²+(7-3)²)=√(9+16)=√25=5

r=5

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.