Question

Can someone help me answer part b please .As I have no idea what it is ?

Answer 1

Answer:

(4,1)

Step-by-step explanation:

Answer 2

Answer:

The coordinates of B is (4,1)

Step-by-step explanation:

You can use the formula of mid-point. It is given that the midpoint of AB is (4,5). So you have to substitute the coordinates of A into the formula :

$m = ( \frac{x1 + x2}{2} , \frac{y1 + y2}{2} )$

Let M be (4,5),

Let (x1,y1) be A(4,9),

Let (x2,y2) be B coordinates,

$(4 ,5) = ( \frac{4 + x}{ 2} , \frac{9 + y}{2} )$

Then you could solve it :

$\frac{4 + x}{2} = 4$

$4 + x = 8$

$x = 4$

$\frac{9 + y}{2} = 5$

$y + 9 = 10$

$y = 1$