try this for answer (11×3.5)-9=x
Answer:
the answer is c
Step-by-step explanation:hope this helped!
Answer:
The answer to your questions is: 25 new teachers
Step-by-step explanation:
Data
# of students = 2000
ratio = 3:80 teachers to students
New teachers = ?
Process
I suggest to use rule of three to solve this problem
3 teachers ---------------- 80 students
x ---------------- 2000 students
x = (2000 x 3) / 80 = 75 teachers
Number of initial teachers = 75
The ratio change to 1:20
1 teacher ------------------- 20 students
x ------------------- 2000 students
x = (2000 x 1) / 20
x = 100 teachers
Number of new teachers = 100 - 75 = 25
What we know is that the sum of a triangle's internal angles are 180º, and a straight angle makes 180º.
first, we have to find the third internal angle(let's call it n) so that we can use it to find the exterior angle.
(3x + 20) + (4x + 5) + n = 180
simplify:
7x + 25 + n = 180
7x + n = 155
n = 155 - 7x
Now we can add it to the external angle to find x.
(155 - 7x) + (8x + 15) = 180
simplify:
170 + 8x - 7x = 180
170 + x = 180
x = 10
Now we can substitute it to the external angle.
8 x 10 + 15 = 95
the exterior angle is 95º.
