Step-by-step explanation:

All the fractions which less than (6/7) will be true
The steps of the solution in the above photo
I hope that is useful for you :)
Answer: 30%
Step-by-step explanation:
It increased by 15 so it increased by 15/50=30/100=30%
I hope this helped!
Quick answer: no you cannot.
Details:
The law of cosines relates between two adjacent sides and the included angle to calculate the third side (opposite to the included angle).
Any combinations of data giving 3 of the above-mentioned pieces of information will enable us to calculate the fourth. Otherwise, the sine rule is used to calculate some of the angles or sides before cosine rule can be used, if at all necessary.