I believe the answer is 17.
The data is a little bit complex,but you can use the knowledge of vector in the subject of algebra,or you can ultimate the basic Euclidean knowledge,like cosine theorem.In detail,you can list two equation with two variable,and get the answer.but i don't finish calculating it.
Just multiply them so first multiply 2.7 times .9 and then times your answer by .6
Answer: x>8
Subtract 8 from both sides -6x< -48 (40 is a negative so -8 will just add to it)
Divide -48 and -6
X< 8 (since they’re both negative it’ll turn into a positive because we divided)
Turn the <
X>8
