Step-by-step explanation:
x = number of multiple choice questions
y = number of short response questions
x + y = 15
5x + 10y = 100
=>
x + 2y = 20
let's subtract the first from the second equation :
x + 2y = 20
- x + y = 15
--------------------
0 y = 5
x + y = 15
x + 5 = 15
x = 10
to graph you need to consider both equations as linear functions. and you need to transform them into e.g. a slope intercept form : y = ax + b
a is the slope, b is the y- intercept.
x + y = 15
transforms to
y = -x + 15
this line goes e.g. through the points (0, 15) and (1, 14).
and
x + 2y = 20
transforms to
2y = -x + 20
y = -x/2 + 10
this line goes e.g through (0, 10) and (2, 9).
the crossing point of both lines is the solution and should therefore be the point (10, 5) as calculated above.
A. but I would double check on that one first.
2/7 because both 8 and 28 are divisible by 4
