On the line segment connecting A and B, the point P is 4/7 of the way from B to A. If ​ for some scalars a and b, what is (a,b)?

On the line segment connecting A and B, the point P is 4/7 of the way from B to A. If $\overrightarrow P = a\overrightarrow A + b\overrightarrow B$ for some scalars a and b, what is (a,b)?