I think it would be the second one
9x-(2x+8)
Distribute the - to both 2x and 8
9x-2x-8
simplify
7x-8
Answer:

Given:
- area = 18 cm²
- base = 6 cm
- height = (h + 1) cm
Substitute the given values into the equation and solve for h:



expand using distributive property of addition
:

subtract 3 from both sides:

divide both sides by 3:

<u>To verify</u>:
Half of the base is 3 cm.
If h=5, then the height of the triangle is 6 cm.
Multiplying 3 by 6 is 18.
This matches the given area, so we can verify that h = 5.
There are multiple answers to this question
Answers: 3.161, 3.162, 3.163, 3.164, 3.165, 3.166, 3.167, 3.168, 3.169
(You can just pick one)
Reason: just look at the place numbers. The number has to be between 3.16 and 3.17. So go to the next place value which is the thousandths place. 3.161-3.169 all are between since they have a 6 in the hundredths place, but does not go over 1.17