Logic Expression

Question

What is the switching expression of corresponding to the equation:

$$F\left(A,B,C,D\right)=\Sigma\left(1,4,5,9,11,12\right)$$

After using the K map I am getting the answer as:

$$\overline{A}\cdot\overline{C}\cdot D + \overline{A}\cdot B\cdot\overline{C}+B\cdot\overline{C}\cdot\overline{D}+A\cdot\overline{B}\cdot D$$

But the answer is given in three terms. Is it possible to reduce something? Am I correct in my approach?

Answer 1

You did not group properly; there should be only 3 groups in your k-map. An online solver produced this:

enter image description here

You probably created another group from elements that were already grouped; perhaps, an unneeded horizontal group in the 1st and 2nd columns is what gave you A'BC'.