Post Secondary Test Prep Day 15 Vocabulary and Practice Notes
1. Setting up a linear equation.
You'll need to know how to set up a linear equation given a word problem.
There are three things you need to identify: the variable, variable change, and constant.
Take a look at this example:
Here, our variable is the number of weekly payments, 𝒘.
The variable change is the amount associated with 𝒘, which
is the weekly cost of $30. And our constant is $60 because it
doesn't change each week - it's just the upfront payment.
So, the total price of $300 is equal to the constant plus the
added-up weekly payments: 300 = 30𝑤 + 60.
2. Graphs of linear equations.
You'll also need to know how to define a linear equation from a graph and how to graph a linear
equation. Here's an example:
Based on the graph, you need to figure out the equation
of the line. We do this by identifying the slope and the
y-intercept. The y-intercept is the easiest one - it's the
value of y the line crosses the vertical y-axis at. In this
case, it's -4.
The slope is the change in y divided by the change in
𝑥 between two points In this case, it's -1.
Our line is then y = -x - 4, which is equivalent to Choice C.
Practice
1.
During the first three months of its life, a breed of exotic fish is born with one stripe and then
develops two new stripes every five days. What is the number of stripes, s, that the fish has at t days
after its birth?
a.
2.
2
t =5 s
b. s = 5t + 1
2
c. s = 5 t + 1
5
d. s = 2t + 1
Which equation best matches the graph of the line shown below?
a.
y−2=4(x−4)
b.
y+2=4(x−4)
c.
y−2=4(x−4)
1
1
d. y+2=4(x−4)
3.
Which of the following points does the line y=
a.
(14, 25)
b. (-5, -3.5)
c. (2, 7)
3
x+4 NOT pass through?
2
d. (6, 12)