9. (a) A man can swim at 2 m/s and walk at 1⋅5 m/s. If he takes x seconds to swim from A to B and y seconds to walk from B to D, fi nd an expression for the length of the journey ABCD, in terms of x and y.
BC
Road Water
A
(b) A woman can swim at 1⋅8 m/s and walk at 1⋅3 m/s. If she takes (x + 30) seconds to swim from A to C and ( y − 10) seconds to walk from C to D, fi nd an expression for the length of the journey ACD, in terms of x and y.
D
10. ABCD is a rectangular frame with a picture inside, as shown.
DC (x + 2) m 1 m
Picture 1 m
1 m AB
Find an expression, in terms of x, for the area of:
(a) rectangle ABCD, (b) the picture, (c) the border.
