The first one is 2x-3y/2
The second one is 1/x+2
The third one is (2x-5y)/(2x+5y)
The fourth one is x^2/z^2
77 unicorns, because yesterday the ratio was 6:5 and today it is 3:4. If you add the numbers for both ratios together, you get 11 and 7. Finding the LCM of these two gives 77 (because 7 and 11 are both prime).
You find the LCM of the sums because when you find values based on ratios, you divide value by the sum of the ratio.
e.g. I have 100 fruits. The ratio of apples to oranges is 2:3. How many apples are there?
To solve this you'd add 2 and 3 (5), divide 100 by 5 (20), multiply that by 2 (40) because that's the ratio of apples to oranges.
In this case, you do the reverse. So If I have 77 unicorns, then yesterday there were (77/11 = 7, 7*6= 42, 7*5= 35) 42 green unicorns and 35 yellow. The sum of 42 and 35 is 77. If you do this process with the other ratio you'll get similar results as well.
The speed of a yacht traveling a distance of 1.357 km in 165 minutes is 0.5 km/h
<h3>What is Speed?</h3>
The speed of an object is the distance covered by the object in respect to time.
Mathematically:


- We know that 60 minutes = 1 hour
- 165 minutes = 2.75 hours

Speed = 0.5 km/hour
Learn more about calculating speed here:
brainly.com/question/4931057
No. 43 is a prime number. It has no other factors besides ' 1 ' and itself.