The coefficients are as follows.
(i) The coefficient of y is -3.
(ii) The coefficient of a is 2b.
(iii) The coefficient of z is -7xy.
(iv) The coefficient of p is -3qr.
(v) The coefficient of y2 is 9xz.
(vi) The coefficient of x3 is 1.
(vii) The coefficient of -x2 is - 1.