Answer:
18. x² + x - 4
20.
or 
22. x² + 2x - 2
Step-by-step explanation:
For some reason my work was unable to be submitted so please see attachment for detailed explanation
The total number of fish available in the tank is (18 + 22) = 40. The probability for 1 goldfish to be taken out would be 18/40. Now, after drawing the first fish, the probability to get another goldfish would be 17/39. And the probability to draw 2 goldfish would be the product of both probabilities. P = (18/40)(17/39) = 51/260 So,the answer is B.
Answer:
4. 9
5. 5x
Step-by-step explanation:
its an isocoles
How about this (see attached image):
Use the four cuts as shown in the image (red lines).
Then assemble 5 equal squares by the numbers: 1 center square and the rest are pieced together using two pieces as shown. All five together add up to the same area as original square because we use all pieces.
The way one gets a hint toward a solution is to see how an area of a square of length 1 can be split into 5 equal square areas:

which indicates we need to find a a triangle with sides 2 and 1 to get the hypotenuse of the right length. That gave rise to the cut pattern (if you look carefully, there are triangles with those side lengths).