Answer:
Total number of points in the test = 100
Total number of items in the test = 40
Let number of items of 2 points be x and number of items of 3 points be y.
Now, using the given information the situation can be represented by using the following equations :
⇒ x + y = 40 .........(1)
⇒ 2x + 3y = 100 .........(2)
The matrix equation is :

By solving the equation (1) and equation (2), we get :
Solution : x = 20 and y = 20
Answer:

Step-by-step explanation:
If A = (-3,-1) and B = (4,4), the slope of AB is

Two perpendicular lines have slopes that have product of -1:

The equation of the line BC with slope -1.4 and passing through the point B(4,4) is

Answer:
10
65
36
90 - x
Step-by-step explanation:
90 - 80 = 10
90 - 25 = 65
90 - 54 = 36
90 - x