Answer: 
Step-by-step explanation:

88 can be rewritten as 8 x 10 and 8 can be rewritten as
making a 2 come out of the root.

10 can be rewritten as 2 x 5.

2*2 can also be rewritten as
making a 2 come out of the root.

We can't keep simplifying the root.
X=2
You add 3x and 4x which is 7x then divide 14 by 7 which is 2
20% off means you pay 80% of the price so you multiply by 0.8, and 7% tax means you multiply by 1.07
Resulting cost = 18.99*0.8*1.07 = 16.26
Hope this helps let me know if im wrong!
i think the answer to this is 3.15