Using excel to solve a value in 2 equations

Hi.
Can some one please help me with this problem (see attached).
I have 2 equations to solve K, that use 4 inputs (A,B,D,H). A,B and D are known. H is unknown. How do i solve for H and K using excel? I know this can easily be solved by manually re-arranging the equation (such that H=1.667 and K=5) however this example is a simplified version of a more complicated sercies of calcs that i need to solve directly using excel (and I believe a macro). Can some one please help.
Many thanks