90. solve r= at a) y = sy+ ax)+ f20- a) (b) y=ja + by) + j2(x - a) (c)y = fy+ax) (d) none of these 91. solve: (d3-4d?d' + 4 dd2) z = 0 (a) z = ¢o)+ ho + 2:x) (b

90. Solve r= at A) y = Sy+ ax)+ f20- a) (B) y=ja + by) + J2(x - a) (C)y = fy+ax) (D) None of these 91. Solve: (D3-4D?D' + 4 DD2) z = 0 (A) z = ¢O)+ hO + 2:x) (B) z = (V) + f20 + 2) (C) z = O) + JO+ 2x) + 20+ 2x) (D) None of these 92. Solve: Ox2 Oy (A) z =Sy+x) + S20-x) (B) z = H* - y) -J2 X - y) (C) z = fy +x) +C (D) None of these 93. Solve: 9tstt=0 (A) z= A)+eJ20-x) (B)z = fO)-ef£0y-) (D) None of these (C)z= O) +eh (y- x)