1) Using a decoder and external gates, design the combinational circui defined by the following three Boolean functions: (a) F₁ = x'yz' + xz F₂-xy'z' + x'y F3=x'y'z' + xy (b) F₁ = (y' + x)z F₁ = (x + y)z F₂ y'z'x'y+yz' 2) Implement the following Boolean function with a multiplexer (a) F(A, B, C, D) = (0, 2, 5, 8, 10, 14) (b) F(A, B, C, D) = II(2,6,11) 3) The adder-subtractor circuit of Fig. 4.13 has the following values for mode input M and data inputs A and B. In each case, determine the values of the four SUM outputs, the carry C, and overflow V. MA B a1 0001 0000 b1 1100 1000 c0 0111 0110 do 1000 1001 el 1010 0101