For the first question the answer is
X=-9 or X=10
First you factor the left side of the question
(X+9)(X-10)=0 then u set factors equal to zero
X+9=0 or x -10=0
X=-9 or X=10
Now for question two is the second bubble of answer
40 liters.....30% is yellow tint
0.30(40) = 12 liters are yellow
if u add 6 liters....(12 + 6) = 18 liters are now yellow...and since u added 6 liters, ur total mixture is now 46 liters.
18/46 = 0.39 = 39% <===
1/4
and 6/4 there we go here is your answer
