Answer:
1.46
Step-by-step explanation:
First find the the mean score before he made a 90.

Now add the score of 90 and calculate.

Subtract the two scores.

His mean test score increased by 1.46.
2.20 rounded to the nearest tenth is 2.2 it is already rounded if it was 2.29 it would be 2.3
Answer:
Honestly agreed, i feel like the smaller grades k- 6th grade are useful. where yoh learn to add, multiply, read time and such.
Remember the properties of logarithms. If you have ln81, you can pull out the power of two (9^2) and have 2ln9. Also, you could do ln9 + ln9 because 9*9=81 and ln9*9 = ln9 + ln9
With these properties, you can get 3lnx+2lny, which is 3u+2v according to the answer.
Hope I helped!
Here you go, hope I helped.