Ok--let's get this sorted out--
Row 1-k1, ssk k9, sl2, k1, p2sso end k9, k2tog, k1
Row 2-k1*p1, k4, (k1, yo, k1)in next st, k4, rep from* p1, k1
You start with 99
So for the first row this is what you do--
k1, ssk, k9, sl2 k1, p2sso(for this you slip 2 st to the r needle, k1, the pass those 2 slipped stitches over the k1 st and off the needle) (repeat between * until you have 12 left, then k9, k2tog, k1
Looks like you have 85 at the end of this row
k1, p1, k4 then you do the (k1, yo, k1) all in one stitch, k4 p1, k1
repeat part between * until you have 2 left
So for row 2, you start with 85 st, but with the increases by k1, yo, k1 in one stitch, you end up with 99 again.
I did the math, and it works out. I would say give it a try and see what happens.
If you do the dec and inc properly, it balances out.