You can't solve this without a total amount. Ask your teacher about this.
Answer:
3 student.
Step-by-step explanation:
From the first statement:
Let the total score be T
Let the total number of student be x
The average of the score = 72
Average = Tota score / number of student
72 = T/x
Cross multiply
T = 72x ..... (1)
Second statement:
One more student took the test and the average becomes 76 with the student having a score of 88.
Therefore,
Overall score = T + 88
Total student = x + 1
Average = 76
Average = overall score / total number of student
76 = (T + 88) /(x + 1)
Cross multiply
76(x + 1) = T + 88
Clear bracket
76x + 76 = T + 88
From equation 1
T = 72x
76x + 76 = 72x + 88
Collect like terms
76x – 72x = 88 – 76
4x = 12
Divide both side by the coefficient of x i.e 4
x = 12/4
x = 3
Therefore, the initial number of the student were 3.
An obtuse triangle has 1 angle with a measurement greater then 90 degrees.
Answer:
To find the point of intersection, you have to set both equations equal to each other and solve. After solving, plug it back into one of the equations. (Its pretty simple so don't worry :] )
y1 = 2x + 4
y2 = 3x-9
y1 = y2
2x + 4 = 3x - 9
4 = x - 9
x = 13
--> Plug x back into an equation for y coordinate. I will be using y1.
2(13) + 4
26 + 4 = 30
y = 30
The point of intersection is (13,30)