we know that
the rule of the dilation about the origin with scale factor K is equal to
(x,y)--------> (kx,ky)
In this problem
k=1 1/2 -----> k=1.5
therefore
A(2,0) -------> A'(3,0)
B(0,-2) -----> B'(0,-3)
C(-2,1) -----> C'(-3,1.5)
D(1,2) -----> D'(1.5,3)