so your equation is
9m = 90 - 25m + 22
the reason is that ∠HLG = 9m
∠GLI = 90, meaning its a right angle
and ∠HLI = 25m +22
putting the equation together, than you just cancle it all out till all you have left is M then you multiply that by 9
i got m = 3 so 9*3 = 27